Datron 4705 User guide

USER'S

HANDBOOK

~

I

PARTNERTECH

SE-597

80

Åtvidaberg,

~--------INSTRUMENTS--~

Sweden

(

4705

1

c:latri

AUTOCAL MULTIFUNCTION 1

CALIBRATOR _

1 I

USER'S

HANDBOOK

for

THE DATRON.4705

AUTOCAL

MUL TIFUNCTION

CALIBRATOR

860064

· Due

to

our

policy

of

contlnuously updatlng speclflcatlon, components and clrcult design matched

to

your Instrument serlal number are avallable on request.

l11ue 1 (November 1988)

our

products, thls handbook may contaln minor dlfferences In

to

the Instrument actually supplled. Amendment.sheets preclsely

..

DANGIR

HIGH VOLTAGE

THIS

...

INSTRUMENT

OF DELIVERING

A

lETHAl

.~

llECTRIC

· ·

..

, < terminals

THIS CAN KILL !

IS CAPABLE

SHOCK

FRONT Full Output Voltage.

Guard terminal is sensitive voltage

or · REAR

carry

to

over-

the

!

..

Unless

it

DO

I+

I-

and

It

your

you

is

safe

NOT

Hi

terminals

NGIR

can

instrument!

are sure

damage

to

do so,

TOUCH

or

Lo leads

that

the

·

i,

CONTENTS

SECTION 1 THE DATRON

Introduction · Standard and Optional F acilities SAFETY Optional F acilities Accessories Additional Documentation Principles of Operation

4705

AUTOCAL

MULTIFUNCTION

CALIBRATOR.

Page

1-1 1-1 1-2 1-3

;.:

,_.\,

1-3

1

..

3,-

1-3 1-4

SECTION 2 INSTALLATION

U npacking and Inspection

. Preparation for Operation

Bench Mounting Rack Mounting Connectors and Pin Designations

SECTION 3 OPE.RATING CONTROLS

· Front Front Panel Keys

Power Switch OUTPUT FUNCTION OUTPUT OUTPUT Frequency MODE I+, Rear Panel

SECTION 4

Preliminaries Limiting Characteristics SAFETY Interconnections Typical Lead Connections General Sequence of Operations

Display Messages

Operating Routines

Test Key

-Test Sequence

W amings and Messages

Pan.el

Switching

Keys

RANGE

Display and t I f Keys

Selection Keys

1-, Hi, Lo, Guard and Ground Terminals

USING

DC

Voltage Outputs AC Voltage Outputs DC

Current AC Current Resistance Additional F acilities Frequency Store 'Spec' Mode 'Error' and 'Offset' Modes Combining Offset and Error Modes

Keys _ .

THE DATRON

4705

2-1 2-1 2-1 2-2 2-2 2-3

3-1 J-1 3-1 3-1 3-2 3-3 3-3 3-4 3-5 3-8 3-9 3-11

4-1 4-1 4-1 4-1

4-1 4-4 4-6 4-6 4-7 4-7 4-7 4-9 4-9 4-9 4-10 4-10 4-10 4-12 4-16 4-16 4-17 4-20

ii

SECTION 5 SYSTEMS APPLICATION

lntroduction lnterface Capability

Bus Addresses

Interconnections Typical System Using the 4705 in a System Programming Instructions

Programming of Operational Functions Programming of Bus Transmissions

of

, Activation

Commands Multiple Commands Operational Sequence Guidelines

VIA

THE IEEE

488

INTERFACE

5-1 5-1 5-1 5-2 5-2 5-3 5-4

5-5 5-8 5-10 5-14 5-14 5-15

SECTION 6 SPECIFICATIONS

General DC

Voltage

AC

Voltage Voltage/Frequency Constraints Capacitive Loading Constraints

DC

Current ,

AC

Current

Resistance

SECTION 7 SPECIFICATION VERIFICATION

Introduction DC

Specification Verification

Equipment Requirements

of

Notes on the Use

the Null Detector

Specification Verification Report Sheet

Verification Procedures

DC

4705 4 705

Voltage Performance-

DC

Current Performance

4 705 Resistance Performance Model 4705 Verification Report Sheet. AC

Specification Verification

RSl

Choice of Verification Method Parameters to be Verified

Summary of Equipment Requirements

Summary of Verification Procedures

Specification Verification Procedures

AC

Voltage Verification Procedure

Millivolts (LF) Verification Procedure

(HF)

Millivolts

AC

Current Verification Procedure

Verification Procedure

Model 4 705 Verification Report Sheet. RS2

6-1 6-1

6-2 6-4 6-6 6-7

6-8 6-1 6-1

7-1 7-1 7-1

7-1

7-2

7-2 7-3 7-3 7-4 7-5

7-7 7-9 7-9 7-9

7-9

7-10

7-11

7-12

7-13 7-14 7-18

7-19

1.

APPENDICES TO SECTION

1.

Verification Procedures

2.

Alternative Millivolt Verification Procedure

3.

Alternative AC Current Verification Procedure using Calibrated Standard AC Shunts

7:

For

4. Total Tolerance Limit Calculations

5.

U ncertainty and Traceability

6.

General Procedural Information

7.

Harmonic Distortion Measurement

Users with Fixed

DC

Voltage Standards

7-21 7-27 7-29 7-31 7-33 7-35 7-37

iii

SECTION 8 ROUTINE

The 4705 Autocal Feature DC

,Calibration Autocal A vailability Zero Calibration Equipment Required for Interconnections DC

Calibration Sequence

4705

DC

Voltage Calibration

4705

DC

Current Calibration

4 705 Resistance Calibration

AC

Calibration

AC

Calibration Sequence

4705

AC

Voltage Calibration

4705

AC

Millivolts (LF) Calibration (lmV-lO0mV)·

4705

AC

Millivolts

4705

AC

Current. Calibration

AUiOCALIBRATION

DC

Calibration

(1

V-lO00V)

(HF)

Calibration (lmV-lO0mV)

(lmA-lA)

8-1 8-1

8-2 8-3 8-3 8-3

8-4 8-4 8-5

8-8

8-10

8-12 8-13

8-15 8-17 8-18

8-22

APPENDIX

4705

TO SECTION 8:

AC

Current Calibration (lO0µA -

lA)

8-23

Inside Rear Cover

DATRON SALES

Note

to

Readers

This handbook has been designed for you to get the best use from your

AND

SERVICE REPRESENTATIVES

WORLDWIDE

4 705. The sections are put together in a

sequence flowing logically from one subject to another, so that understanding increases as the text is read

is

naturally from front to rear. Here

Sect

1 . Introduction and· a brief account of the interna! design.

Sect

2. Physical connections and mounting - getting it installed.

Sect

3.

A brief scan of the available controls - where they are and what they do.

Sect

4. The correct procedures for making the 4 705 perform for you.

I

Sect

5. How your 4705 can operate within an

an alternative ( explanatory !) version of the Section Titles:

IEEE

488

system-

the device dependent codes you will need

to use.

Sect

6. Specifications - what accuracy you can expect to get from your instrument.

Sect

7. Verification that your 4705 matches the high specification it had when it left the factory.

Sect

8.

How to restore your 4705 to its original specification after it has suffered the ravages of time ·and temperature.

We are confident that your will

use this handbook to obtain maximum benefit from its many facilities.

4 705 will give you many years of accurate and reliable service, and hope that you

iv

SECTION 1 THE DATRON

AUTOCAL

MULTIFUNCTION

4705

CALIBRATOR

I

General

View

of Datron

4705

Autocal Multifunction Calibrator

lntroduction

The Datron 4 705 Autocal Multifunction Calibrator

It

is

and full systems capability. Current and Resistance functions in a single unit.

The basic instrument includes both calibration sources.

The 4 705 incorporates a reference module containing precision temperature-compensation elements,, maintaining a high accuracy specification over the ambient temperature range of 23 °C stability 'Autocal' feature ensures that its 24-hour specifications are usable; not merely figures

The 4 705 uses a microprocessor such as palibration remote programming capability, allowing programmed calibration

is

achieved by use

of

hi~-quality digital multimeters. The

characterized by

DC

Voltage,

super-selected reference components and ultra-stab

for'

control management, simplifying its use in complex manual operations,

is

a high-precision calibrator which features high stability

·a

wide-range coverage

AC

Voltage,

DC

of

DC

Current,

Voltage,

AC

Current and Resistance

AC

Voltage,

+ 10°C. A high level

le

gain-defining resistors. The

of

merit.

IEEE

488 interface provides a comprehensive of

the 4705 itself.

DC

of

1-1

----.

-

--

____________

___;

____

_

Standard and Optional Facilities

I

DC.

Voltage Ranges

The instrument provides facilities in eight decade ranges from + +1100V. on the + 1 000V range, when the output is limited to

1100V.

100% overrange

DC

Voltage calibration

100µ,

is

incorporated, except

V to

Resolution and Accuracy

The maximum resolution facility for displaying the specified accuracy of any output voltage. The 4705 specification Section

6.

is

6½ digits with a unique

is

in

AC Voltage Ranges

The instrument provides

facilities in seven decade ranges from. 1 m V to

1100V. the 1000V range (see page 3-6), when the output is limited to 1100V.

DC Current Ranges

The instrument can be used to calibrate

in

AC Current Ranges

The instrument can be used to calibrate

in five decade ranges from 100µ,A to 1 A.

Resistance

The instrument can be used to calibrate resistance in

eight decade ranges from

l00%

five

decade ranges from 100µ,A to 1 A.

overrange

_AC

Voltage calibration

is

incorporated, except on

DC

Current

AC

Current

l0ohm

to l00Mohm.

Resolution and Accuracy

The maximum resolution facility for displaying the specified accuracy of any output voltage. The 4 705 specification

Section

Resolution and Accuracy

The maximum resolution facility for displaying the specified accuracy of output current. The 4 705 specification Section

Resolution and Accuracy

The maximum resolution facility for displaying the specified accuracy of output current. The 4 705 specification is in

Section

Resolution and Accuracy

The maximum resolution facility for displaying the specified accuracy of any output resistance. The 4 705 specification is in

Section

6.-

6.

is

5 ½ digits with a unique

is

5 ½ digits with a unique

is

5 ½ digits with a unique

is

6½

digits with a unique

is

ih

in

Frequency

The output frequency

l0Hz

to

l00kHz at a resolution Any five frequency values within the range instrument can be stored in volatile memory.

in four overlapping decade ranges,

of

1 %

of

the 4 705 extends from

of

nominal Frequency Range.

of

the

Autocal

All Datron A make the removal of the covers for calibration unnecessary, as and functions can be carried out from the front panel or over the

Accidental or unauthorized use of the calibration routine instrument rear panel. The procedure for calibrating this instrument

1-2

UTOCAL

full

IEEE

is

prevented by a key-operated switch on the

is

instruments are designed to

routine calibration of all ranges

488 bus.

coptained in Section

8.

Output Deviation ,

A user may deviate the output voltage from the output display value by introducing a gain 'Error' within the general range DC

functions, the output may be 'offset' by up to +

2%

of the range in use, or 200µV, whichever

greater.

+ 10%. Additionally, for

is

Remote Sense

The specified output voltage may be sensed at the load, using 4-wire connections. Remote or Local

is

Sense

selectable from the front panel.

Remote Guard

This facility aliows the instrument' s interna! guard shields to be externally connected.

--------

.....

111!!!!1!!!!!!~~~~~~~~~========··-·=---=·-·=···=······=-·

=····=··-=··-··--··--···--·-··-··--··

··--

..

·····

--·--•·······---'------__:c...:...:~-

Self-test

· On power-up, the intemal calibration memory automatically checked. is

off and not under remote control, a user may . conduct a sequenced test of the displays, keyboard, safety circuitry and Reset function.

Message

Messages to the user are presented on the display: The two main groups are:

Fail

An intemal fault condition has been detected.

Error

A user has selected a instrument' s capability.

At

any time when the output

Readout

task

which

MODE

is

outside the

Systems Use

The instrument can form part of the method of connecting to the system controller and the command codes are described in Section

IEEE

488 standard digital interface. The

of

a system by means

5.

SAFETY

is

Optional Facilities ·

The available options for the 4 705 are Option 42: Rear output terminals ( as a factory-

fitted alternative to front panel terminals).

NB: The rear 'output option

recommended for best performance in calibrating high bandwidth, low level instruments.

Option 90: Rack-mounting kit.

as

follows:

is

not

Accessories

The instrument accessories:

Description

Power Cable Set of Calibration keys U ser' s Handbook Calibration and Servicing Handbook (2 volumes) · (Volume

In addition the following accessories are available

for use with the 4705 instrument:

is

supplied with the following

Part Number

1)

(Volume 2) 850065

920012 700068 850054

850063

For

protection of the user, safety trip circuits are incorporated to switch the event of instrument faihires which might generate dangerous output voltages.

UNDER USERS

SENSE

THEY ARE FIRST SATISFIED THAT· NO

DANGEROUS

NO CIRCUMSTANCES ·

TOUCH ANY

OR

GUARD

VOLTAGE IS PRESENT.

OUTPUT

OF

TERMINALS

OFF,

THE OU'IPUT,

in the

SHOULD

UNLESS

Description Part Number

RMK Rack-mounting kit (Option 90) 440094

Special Lead Kit 440070

Additional Documentation

The Calibration and Servicing Handbook contains information required to adjust and service the 4705

It

instrument. circuits, trouble-shooting and calibration procedures, parts lists, layout drawings and circuit diagrams.

contains detailed descriptions of the

1-3

Princ.iples of Operation

----

Galibration

Memory

..._

__

__,~

Front Panel Keys

->

Local Gontrol

lnputs

Gal

.-

Run

Micro-

processor

Gontrol System

,.

i---.

Glock

&

Gounter

+

Precsion Electronic

Divider

I

AG

DG

Master

Reference

Voltage

+

Voltage Ranging Gontrol

Frequency

Synthesizer

-

&

Oscillator

Output

Error Feedback

AG

Reference

~

Generator

,__

Output and Terminal Switching Gontrol

___.

i--.

Voltage

Gontrolled

Amplifier

Amplitude Sensing

Gomparator

"

AG/AG

f----+-

1..--

Ranging

and

Output

Switching

'

-

I+

~

-

I-

...

-

Hi Lo

>AGV

'

....,

1+

I

I-

-

i

....,

Hi

I

Lo

-

....,

Guard

Remote Gontrol

lnputs/Outputs

__

0.;:;...._

IEEE

488

lnterface

..._

__

I\.

DG

I

,...___

Out Guard

·

_,

_.,

In

Guard

DG

Reference

Voltage

Gurrent Ranging Gontrol

I

Resistance Ranging Gontrol

I

L--------------------------------------------

Voltage Ranging Gontrol

Gurrent

AG

Gurrent Reference Voltage

~[

Voltage I

lo

Guri'ent

~

Gonvertor

1

Gurrent and Resistance

1

-

.

Ranging

and

Sensing

Gurrent

- r

~J

Ranging

/ r

r ..

_

· I Resistors

Prec1s1on

,Il

f T

':

I+

.

I-

"P'

-

.

"P'

-

.

Hi Lo

AGI

I+

I-

I•

~~

I-

-

l

Simplified Functional Diagram . This shows the division and flow of functions within the 4705.

lnputs

The 6802 microprocessor controls the output in response to three main inputs:

adjustable 'Working' reference voltage between 0V and 20V, whose value depends on digital inputs from front panel keys and calibration rriemory.

i)

Front panel keys.

ii)

IEEE operation.

iii) Corrections placed in non-volatile memory

<luring values which control the output.

488 bus messages in 'Remote'

'Autocalibration'. The se modify the

Precision Electronic .Divider

In the out-guard section the selected output value,

including calibration corrections, comparator as a 25-bit number. This by a crystal controlled binary counter, resulting

125Hz square wave whose mark : period ratio After processing, the computing system changes the output

of

the instrument to respond to the input

instructions.

accurately represents the output value selection. When transferred into guard, it chops the Master Reference voltage. A 7-pole active low-pass filter integrates the chopped reference, to generate the

Reference Voltages

A 20V

the fundamental accuracy

DC

'Master' Voltage Reference establishes

of

the instrument. From

this 20V, a precision electronic divider derives an

ripple-free

DC

Working Reference Voltage.

DC Voltage Output

The

working reference for

DC

V oltage

)DGV

%

Ref

} ·i'

DGI

}

Ohms

is

set into a digital

is

counted out

Output

Ground

in

a

is

1-4

a stable resolution between O and

DC Voltage Ranging

Low Voltage Ranges

, range

(+19.99999 working reference. The 1 V and 1 achieved

The 1

DC

voltage, accurately variable

+ 20V.

(100µ.V-

of

the 4 705

is

Full Scale), derived directly from the

by

attenuation:

00m

V range attenuator is also used for 1

10V

+ 1 0V Full Range

00m

at

high

FR).

The

basic

V ranges are

Om

1 m V and 100 µV ranges, and the digital input to the

precision divider is scaled to provide the correct

working reference values:

Range

l0mV

lmV

l00µV

High Voltage Ranges

The 1 00V range working reference.

AC

up

transformation.

W orking reference values

-2V

- + 2V

-200mV

-20mV

(1

00V

is

a direct amplification

The

1000V range employs step-

- + 200mV

- + 20mV

and 1

000V)

of

V,

the

Quadrature Oscillator

The oscillator' s output frequency demand, between

l0Hz

and

is

l00kHz,

set close to any

by selectingthe RC time constants ofits dual integrators; and then by correcting

to

the actual demand by phasecomparison with the output from, the synthesizer. The output sinewave purity and constant amplitude are precisely defined by a sophisticated control loop, and the RMS value

of

the sinewave is adjusted to be

roughly proportional to the demanded output voltage

data

or current. Timing synchronize the actions Generator and

Voltage-Controlled Amplifier (VCA}

AC/

is output from the source to

of

the A C Reference

AC

Comparator.

This has variable gain, amplifying the output from the Sinewave Source and providing a buffered drive to the output circuits. Its gain is determined by the measured difference between the sensed calibrator output and the the

VCA

provides the correcti'ng fine adjustment för

values

AC

Reference; so

of

the

RMS

the output amplitude loop.

AC Voltage Ranging

Output Switching.

In

addition to switching between functions, the output switching circuits isolate terminals on Sense and

AC Voltage Output

Guard

The working reference for stable

DC

voltage, accurately variable at high

resolution between

AC Reference Generator

· The higher accuracy AC/DC)

is exploited

O UTPUT O FF. Remote/Local

switching is incorporated.

AC

Voltage Output

+ 0.1 V and + 2V

of

AC/

AC

by

converting the

DC.

comparison ( over

DC

Working Reference into a stepped waveform whose characteristics match those

of

amplitude

controlled by the

Sinewave Source

Frequency Synthesizer

From

the frequency value set into the

FREQUENCY

this 'Quasi-sinewave'

DC

W orking Reference value.

display, the processor controls the

of

a sinewave. The

is

precisely

MODE/

synthesizer using an encoded 9-bit command. The synthesizer translates the command into a pulse train at a crystal-derived frequency between 240kHz

for,

and 4MHz, to be divided down

use as phase-

reference for the Quadrature Oscillator.

N.B.

lf

required, the Frequency Synthesizer, can

toa

be locked

customer's

1MHz

or

10MHz

frequency, input via J53 on the rear panel.

isa

1V

Range

This is the basic the

AC

working reference is variable between 0.1 V and 2V RM~, it is compared in sensed output. directly to the output

1

00mV, 1 Om

The 1 V Buff er output is reduced

AC

The

1 V Buffer output

V and 1

voltage range

I+

and I - terminals.

mV

Ranges

of

the 4705.

1:

1 ratio with the

is

thus passed

by

precision

As

attenuators before being connected to the terminals, ,

the level being sensed before attenuation.

1

0V, 1 00V

The 1 V Buffer output is amplified on each ranges. A separate amplifier is provided for the 1 range, the output sense signal being obtained

and 1

000V

Ranges

of

these

0V

at

the terminals and attenuated before coinparison with the reference. A common power amplifier is used for

On

the

l00V

both 100 V and 1000V ranges.

Range

the output is fed directly to the terminals, on the

is

1 000V Range the output On

both ranges, the sensed terminal voltage is

stepped up by a transformer

reduced to the reference lev el by precision attenuators.

Output Sensing

On

the 1 V range and above, the output

the front panel

Hi

and

Lo

terminals. With Remote

Sense selected, these are isolated from

but in Local Sense Hi is internally connected to and

Lo

to

I-.

As

described above, the lOV, 100V

and 1 0Ö0V ranges' sense signal

is

sensed at

I+

and

I-,

I+,

attenuated before

comparison with the reference.

-·-----

1-5

AC/

AC

Comparator

The comparator generates an error voltage proportional to the difference between the RMS values of the alternately samples a number

AC

reference and the sensed output. It

of

cycles from its

'Ref and 'Sense' inputs, computes and integrates the squares

of

their instantaneous values, and uses a 'Sample and Hold' technique to subtract one from the other, this being the 'error' voltage to control the VCA. The loop thus controls the 4 705 output so that the RMS value equates to that

DC Current

On changing functions to

Reference voltage

of

the comparator' s sense input

of

its reference input.

DC

Current, the W orking

is

switched to drive a voltage-to-

current converter, and the OUTPUT display legend is

changed to µA,

is

provided, and the Output lines are fused.

AC Current

An

AC

Current output

current converter. The 100

mA

or A. Over-voltage protection

is

produced by the voltage-to-

µA

and 1 A ranges are

driven directly from the basic 1 V range, and the others from the 1 achieved

,by

protectiori against over-voltage

OV

range. Range selection is

switching internal shunts. Output

is

provided, and the

output lines are fused. The OUTPUT display legend is

altered to µA,

mA

or

A.

Autocalibration

By setting the CAL

the rear panel to

·calibrated. (Refer to Section 8). The output value measured and the microprocessor

ENABLE_

security keyswitch on

ENABLE, the 4705 can be

is

activated, to

is

add any new corrections to factors already retained

in

non-voltai_le

factors are applied in the normal R

Processor

memory. The updated correction

UN

mode.

A 6802-series microprocessor controls the intemal performance 26K

bytes

2K

bytes

space, and

of

the instrument, employing

of

program memory.

of

memory are used for stack and work

2K

bytes are made non-volåtile by a battery-pbwered back-up supply, storing calibration correction factors.

With the exception

ofthe

Power

ON/OFF

switch, each front and rear panel control provides an input to the microprocessor system, which translates the information to command the

4 705 analog and

calibration functions. The processor also controls the display, the

IEEE

488 Interface Bus and the operation

of

the

restart and error circuitry.

Resistance

Remote Sense. One

resistors

I-,

is

internally 4-wire connected to the I+,

Hi and Lo terminals by operation

of

a set

of

eight precision

of

each

RANGE key. Simultaneously the 4-wire calibrated

value

of

the resistor

is

displayed (OUTPUT

display). Pressing the OUTPUT Zero key connects a true 4-wire short to the terminals, and the 0 UTPUT display indicates zero. This zero display value cannot be recalibrated.

Local Sense (Remote Sense LED Unlit).

The

connections to the resistor remain the same, hut the display value includes the resistance of the connections form the

Hi

and Lo terminals to the

resistor. The arrangement provides a calibrated 2-wire facility with external connection to the Hi and

Lo terminals. The Zero key shorts the Hi and Lo

terminals, terminals

. When

4

705

in

this case the resistance between the

is

displayed and may be recalibrated .

n

is

selected from any other function, the

is

forced into Remote Sen se, hut this may be

deselected for 2-wire operation.

1-6

SECTION 2 INSTALLATION

This section con~ains information and instructions for unpacking and installing the Datron

Unpacking and lnspection

E very care to ensure that your equipment will reach you in perf ect condition.

If

the equipment has been subject to excessive mishandling in transit, the fäet will probably be visible as extemal damage to the shipping carton. the event cushioning material should be kept for the carrier' s inspection.

Unpack the equipment and check for extemal damage to the case, sockets, keys etc. found, notify the carrier and your sales representative immediately.

Standard accessories supplied with the instrument are as described in Section

is

taken in the choice of packing materials

of

damage, the shipping container and ,

If

damage

1.

lt;i

is

Power cable

The detachable supply cable, comprising two meters of 3-core PVC sheath cable permanently moulded to

. a fully-shrouded 3-pin socket, fits in the

INPUT

home. · The supply lead should be connected to a grounded

outlet ensuring that the ground lead Connect Black lead to Line, White lead to Neutral and Green lead to Ground. (European: Brown lead to Line, Blue lead to Neutral, and Green/Y ellow lead to Ground).

Line voltage

The 4 705 100/l To board

plug recess, and should be pushed firmly

is

operative within the line voltage ranges

15/120/220/230/240V

accommodate the ranges, a small

is

housed beneath the POWER FUSE.

+ 10%, 50 or 60Hz.

Preparation for Operation

4705.

is

PC

POWER

co~nected.

selector

DANGER

THIS INSTRUMENT IS CAPABLE OF DELIVERING A LETHAL ELECTRIC

I+,

I-,

SHOCK. THE ARE MARKED WITH WARN USERS

UNDER USERS TOUCH ANY OF THE FRONT TERMINALS UNLESS THEY ARE FIRST SATISFIED THAT NO DANGEROUS VOLTAGE IS PRESENT.

Power lnput

The recess POWER INPUT plug, POWER and LINE VOLTAGE SELECTOR are contained in

an integral filtered module at the center

panel. · The protective window allows the fuse rating and

line voltage selection to be inspected with the power socket connected. This window slides to the left once the socket has been disconnected, for access to the fuse and voltage selector printed circuit board.

NO CIRCUMSTANCES

Hi and Lo TERMINALS

~

SYMBOL

OF

THIS DANGER.

TO

SHOULD

FUSE

ofthe

rear

\

220

Operating Voltage Selection

FIRST ensure the POWER CABLE

Slide the window to the left to reveal the fuse and selector board. Draw the fuse-extractor to the left and remove the fuse. Remove the desired voltage Reinsert the selector board firmly into the module slot. The desired voltage fuse. Retum the fuse extractor to the normal position. Insert the appropriate

Slide the window to the right and insert the

CABLE.

Power

The fuse rating

3.15A for 220/240V line supply

6.25A for

Fuse

PC

selector board and rotate until the

is

on the left

is

visible in the cutout below the

is:

100/l

20V line supply

POWER

of

the upper surface.

FUSE

OOL

is

removed.

(see over).

PO WER

PC

D

is

located behind the window in the POWER

It

INPUT

the anti-surge or SLO BLO type.

module on the rear panel, and should be

of

2-1

WARNING MAKE SURE THAT ONLY FUSES WITH THE REQUIRED RATED CURRENT OF THE SPECIFIED TYPE ARE REPLACEMENT. THE FUSES

AND

THE SHORT CIRCUITING OF

USE

USED

op'

AND

FOR

MENDED

FUSE-HOLDERS · SHALL BE AVOIDED,

AND

RENDERS THE WARRANTY VOID.

Bench Mounting

Th,e

instrument

is

fitted with six plastic feet.

It

is

intended to stand flat on a bench, positioned so that

the cooling-air inlet and exhaust apertures are not

obstructed.

( 12 inches) of free space

It

is.

recommended that at least 30cm

is

at the rear.

R~ck Mounting

Option 90 permits the instrument to be mounted in a standard 19 inch cabinet. ·

Remove the two rear spacers from the case sides by releasing six screws. slides to the rear

Fit

the two rack-mounting

of

the case sides and secure using

six of the shorter screws in the option kit.

N.B. The slides may be reversed to give rearward

extension.

Fit

the two rear rack-mounting ears tq the rear ofthe

In

cabinet, with tongues facing forward.

shallow

cabinets it may be necessary to trim the tongue.

CAUTION

is

Assistance

required to fit the 4705 into the

cabinet.

Lift the 4705 into position in the cabinet, locate the

tongues in the slides, and carefully slide backwards

until the front ears hutt up against the cabinet front.

Secure the front ears to the cabinet. Also clear

ventilation for fan

cooli11g

to opera te properly.

I

To Fit Option

90

CAUTION

is

Note that the 4705 front and

rear.

AT NO TIME should the 4705 be

designed to be supported

supported only by the front brackets.

and

account should the upper

lower covers be

removed.

SUITABLE RACK DEPTHS

DEPTH

0 REMOVE

2 OFF 450300 REARSPACERS

6 OFF 611038

M4X12mm

mm

<635

635-735 25-29

735-800 29-31;

SOCKET HD CSK SCREWS

in

<25

FIT

REVERSE RACK

at

On

no

NOTES

SHORTEN REAR RACK

MOUNTING

AS

SHOWN

SLIDES TO EXTEND PAST

EARS

BY DRAWING

MOUNTING

REAR PANEL

0 FIT

2 OFF 450312 RACK 2 OFF 450313 RACK 2 OFF 450314 RACK

12

AS

INSTRUCTED

OFF 611062

MOUNTING MOUNTING MOUNTING

M4X8mm

SOCKET HD CSK SCREWS

EAR FRONT EAR REAR SLIDE

2-2

@

©

Connectors and Pin Designations

IEEE

488

lnput/Output

The

IEEE

input/ output

is

a 24-way connector that

directly compatible with the

IEC

the

Pin Layout

Pin Designations

J27

PinNo

1

2

3

4 5 6 7

8

9 IFC Interface Clear

10

11 12

13

14 15

16

17 18

19 20 21 22 23 24

625 Bus.

12

\

24-Pin

Socket )

24

Name Description

DIOl

DIO2

DIO3 DIO4

EOI DAV Data Valid NRFD

NDAC Not Data Accepted

SRQ ATN Attention SHIELD

DIO5 DIO6 DIO7

DIO8 REN GND6 GND7 GND8 GND9 GNO GNDll GNO

Data Input Data Data Data End

Not ready for Data

Service

Screening on cable ( connected to 4705 Safety Data Data Input Data Input Data Input Remote Enable Gnd Gnd Gnd Gnd

10

Gnd Gnd

4705 Logic

to

4705 Safety

Output

Input

Output

Input

Output

Input

Output

or

Identify

Request

Ground)

Input

Output

Output Output Output

wire

of

twisted pair with DAV

wire

of

twisted pair with

wire

of

twisted pair with NDAC

wire

of

twisted pair with IFC

wire

of

twisted pair with

wire

of

twisted pair with ATN

Ground

Socket

IEEE

Ground)

J27.

488 interface and

13

Line 1 Line 2 Line 3 Line 4

Line 5 Line 6 Line 7 Line 8

(lnternally connected

NRFD

SRQ

is

External Reference Frequency lnput

Socket

J53

This BNC socket intake filter.

is

located next to the cooling air

It

enables the frequency synthesizer to be locked to a customer' s own frequency standard provided that it meets the following criteria: Voltage: 500mV to 15V peak-to-peak. Frequency: 1

N.B. The socket has an input resistance

approximately

Externa1· Reset Socket

Pin Layout

MHz

± 1 % or 10MHz + 1 %

500

J54

8

of

ooeooooo

000000•

15

9

Pin Designation

J54

1-5

6

7-8

Signal

Not

used Reset line Not

used

9 Reset common

10-15

N.B. Some

of

the 'not used' pins may be wired for

factory test purposes.

Externa! Reset

Switch

Not

used

Wiring

Rear Output Terminals (Option

The 4

705

is

fitted with either six front panel output

42)

terminals or six rear output terminals. The Rear Output alternative

is

fitted at the customer's request

only at manufacture.

The

4

705

cannot be fitted with both front and rear

output terminals.

The functions of the six termina

1

ls

are identical to those normally fitted on the front 'panel, and the externa} leads are connected in the same way. (See Section 4 for details).

Reset

common

Socket

J54

2-3

DANGIR

THIS

A

llTHAl

HIGH

VOLTAGE

INSTRUMENT

OF DELIVERING

lllCTRIC

...._

..

(

4

THIS CAN KILL !

FRONT

terminals Full

or

Output

IS CAPABLE

SHOCK

REAR

carry

the

Voltage.

I

Guard terminal is

sensitive voltage

It

can

your

Unless

. it is safe

DO

I+

you

NOT

I-

and

Hi

terminals

instrument!

are sure

TOUCH

or

to

damage

to

do

so,

Lo

leads

over -

that

the

2-4

DANGIR

SECTION 3 OPERATING CONTROLS

This section summarizes the main operating features Section 4. ·

Front Panel

MODE FREQUENCY

DANGER "I

HIGH VOL TAGE

~A

I+

I-

Guard

@@@

~{t)4)

\.

-=-

~

FREQUENCY RANGE

Store 100

1aaaaaa

-

F1 . F2

1k

10k

100k

F3

F4

FS

199ggg9

Guard Sen se Spec Error Offset Test

- Remote -

STO

MODE

SET

±0

CAL

of

the 4 705.

For

detailed operating procedures refer to

OUTPUT

,-,,-,nnn;n v

·uuu,uLu,

OUTPUT RANGE

1äBåeieletäå

100

1000

1k0

10k0

100k0

1MO 10MO 100MO

1ra9991~~99

O I AC

FUNCTION OUTPUT

DC

Reset

_:

ON ~ OFF

rdatron"

INSTRUMENTS

4705

AUTOCAL

MULTIFUNCTION

-..

CALIBRATOR

Power

.,

Power-up State

The controls are outlined in blocks, left and right,

The

associated with the appropriate display.

righthand blocks generally deal with function and output definition, whereas the left-hand blocks are concemed with frequency, mode and terminal configurations.

Front Panel Keys

All user commands from front panel keys are executed through main program firmware. A Key · LED

lit signifies that conditions are valid for the selected operation, and not merely that the key has made contact. ·

At

any time, the instrument status

of

combination

LED

states, display values and

is

described by the

display messages.

is

Gene·rally, if an invalid condition

selected, an error message will be displayed and a buzzer will sound, the command is ignored and the remains

in

its previous state.

4

705

Power

Switch

WARNING THE POWER SWITCH SHOULD NOT BE

TO

SET

AND

ON UNTIL THE LINE VOLTAGE

POWER FUSE RATING HAVE BEEN SELECTED AS DETAILED IN SECTION 2 (INSTALLATION)

When set to the m

Power switch isolates the instrument from the

OFF

position, the 2-pole

supply.

I:]

ON,

When switched to

up, runs a self-test program and

the instrument powers

is

configured into the

following state: OUTPUT

FUNCTION OUTPUT OUTPUT

RANGE DISPLAY

FREQUENCY

RANGE

OFF

DC

1 .000,000V

Not

selected

MODE/FREQUENCY

DISPLAY

MODE

Guard Sense

LEDs

Key

Lit

Blank Not

selected Local connection ( unlit) Local connection ( unlit) OUTPUT

OFF,

DC,

1

3-1

QUTPUT

Switching

OUTPUT RANG E

100µ 1m

0

FUNCTION

-

OUTPUT

The 4 705 should normally be connected and set up with its

Lo

of

MODE

lit.

Pressing the OUTPUT I - Hi and

'

circuits.

ON/OFF

output off. This isolates the

terminals from their interna! circuitry regardless

RANGE- FUNCTION, FREQUENCY or

sele~tions.

Lo

'fhe

terminals to their energized interna!

10m 100m 10 100 1000

I

AC

I+,

I-,

Hi and

OUTPUT

ON

key connects the

OFF

LED

I+,

is

datrc:n

INSTRUMENTS

4705 , AUTOCAL

MUL TIFUNCTION

CALIBRATOA

r70

Power

••

OUTPUT

Under certain abnorma! conditions which might compromise safety, the 4705 output will trip off, accompanied by a display. Control keys.

If

the F AIL, 5 message

automatic recovery from the tripped state whether interna! conditions have or have not returned to normal.

OFF Trip - Fail 5 Massage

FAIL 5 message on the

is

removed from the front panel

is

present, there

MODE

is

no

OUTPUT

Certain instrument states are prohibited,. and some transfers between states are restricted by program firmware. result in the output being switched Sectiön 4, Operating Routines.

OUTPUT

On Output terminals switch the output on, as labelled. In addition, polarity may be reversed by using the step the output across zero value. The

describe the polarity AT THE OUTPUT

TERMINALS,

"error" and "offset" modes these two could be

opposite).

In functions, the outputs to appear at the output terminals. The

key will cause the error buzzet to sound and

Error 8 to appear in the

display.

3-2

OFF Default

For

safety reasons some

ON - +

DC

Voltage or Current, the polarity at the

is

determined by the Key

of

these transfers

off. Refer to

+ I + keys to

not on the OUTPUT display. (In

AC

Voltage,

AC

Current and Resistance

ON + key will cause the selected

MODE/FREQUENCY

O N

us~~

LEDs

ON

to

-

Reset Key

The Reset Key has two functions:

1.

It

allows a user to reset the safety trip to test

whether conditions have returned to normal. they have; the F AIL message will disappear, the previous instrument state will be restored but with

OUTPUT OFF, and front panel control

will be returned to

abnorma! the further attempt may be made after a suitable interval. The

'Test' mode. ·

2.

It

returns the instrument to power-up conditions

in all cases except the following:

• Self-test mode

• F AIL conditions

• In remote control mode ( where it

inoperative

Other Massages ;

A full list The fault conditions which generate Fail messages are analyzed Handbook.

of

4

705

in

tb-e

user.

If

conditions are still

F AIL state will persist, and a

Reset

LED

is

inoperative except in

is

).

messages appears in Section

the Calibration and Servicing

If

4.

FUNCTION

Keys

100µ 1m

Selected Function

DC AC

n

DC AC

OUTPUT RANGE

10m 100m

and I

10 100 1000

Reset

_:

OUTPUT

ON

~

OFF

Specified Output

DC

Voltage

AC

Voltage · Resistance DC

Current AC

Current

When output is automatically set to from automatically set to zero.

OUTPUT

new function, the

changing from one function to another the

OFF.

n,

to AC

RANGE

When

or

DC, the OUTPUT value is

If

the corresponding

or value is not available on the

4 705 displays

Error

changing

8 and sounds

its error buzzer.

n selection forces the 4 705 into Remote Sense for

4-wire operation.

OUTPUT RANGE

Each

OUTPUT

selected by the user, setting the legend and decimal point on the

OUTPUT display to match. Full range

values for voltage and current are marked above the keys. Nominal values

n function are marked below the keys.

the

OUTPUT RANGE

100µ 1m 10m 100m 1 10

100

1000

Voltage and current ranges are selectable as follows, the actual output value being selected by use

OUTPUT display tl, keys:

DC

1aaaaaaaa

100

1000

1k0

10kO

100k0

1MO

AC DC AC

Voltage

Current

Resistance

o

FUNCTION OUTPUT

AC

DC Reset

_:

ON

~

OFF

If

OUTPUT is

remains on unless the change ranging-up to more than 75V RMS in DC

on

l00V

range. In these cases OUTPUT

defaults to OFF. Any range selection which would exceed the internally de

frequency limit

limits are described on page 3-6.

Keys

RANGE

key scales the output as

of

each precision resistor for

100µ,V to 1000V lmVto 100µ,A to 100µ,A to lO!l

ON

is

automatically inhibited. These

1000V RMS

IA IA

RMS

to

lO0M!l

when changing ranges, it

is

to 1 000V range, or

AC

or 1

fin

ed voltage-

of

I0V

the

in

3-3

Key

se.ections

100µ

10

lm

100

10m

lk

100m 1

10k

100k

10

lM

100 1000

lOM

lO0M

DC

Voltage

AC

Voltage

DC

Current

AC

Current

Resistance

OUTPUT

Output Resolution

The Output and display

Range

DCV ACV DCI ACI 0 (2-wire)

0 (4-wire)

Display and t

I · 11 11 11 11 9

- -

_,

l00µV

*

l00µA l00µA

100

lmV

lmV lmA lmA

1000

* Error 8

I+

Keys

OUTPUT

- -

are_

resolved as follows:

100µ

10

3½

5½

5½ 3½

6½

.lm

100

4½

3½

5½

5½ 5½

6½

l0mV l0mV l0mA l0mA

IkO

~

10m

lk

5½

4½

5½ 5½

6½

l00mV l00mV l00mA

l00mA

l0kO

100m

10k 100k

6½

5½ 5½ 5½

6½ 6½

lO0kO

6½ 6½

5½ 5½ 5½

6½ 6½

IV

IV lA lA

1

lOV lOV

100V 100V 1000V

1000V

* * * * .

lMO

10 100 1000

lM

5½ 5½

6½ 6½

·*

lOMO

lOM

6½

6½ 6½

l00MO

100M

6½

5½

6½ 6½

*

The O which always indicate the correct units for the Range and Function selected.

Output and Display Control

Each display digit above the display may be set within the range permitted by the function selected. key adds 1 to its digit: pressing the

If

also changed by the same increments as the display

( subject to the instrument interlocks

On O ranges, only the overrange t I t keys are

operative. These duplicate the action

Range/Zero Keys.

The Resistance value displayed value the nominal value periodic calibration. The value displayed depends on the selection

3-4

UTPUT

vertical pair

display

of it.

Each

is

supplemented by legends,

+ I + keys is assigned to the

Thus the value registered on

momentary press

t key subtracts

OUTPUT

of

is

ON,

the Output terminal value is

).

is

the calibrated

the standard internal resistor selected ( not

).

This may · be updated

of

Local (2-wire) or Remote (4-

of

the Full

of

the •

<luring

1.

wire) Sense, and should be recalibrated in the correct Sense mode (See Section

Auto-1 ncrement/Decrement

When a + I t key is pressed for more than ½ second,

is

its digit approximately 3 digits per second until the key is released.

Overflow and Underflow

As a digit is stepped from 9 to 0, the value ofthe next higher-order digit

0 to 9 decreases the value by

therefore acts as a counter, with full 'carry' and

'borrow' action.

Range of Adjustment for DC Functions

The

+It

minimum

l00mV

for Current Ranges. The 1 00µV Range has a Full

Scale

ranges are truncated.

increased or decreased

is

increased by

keys adjust the readings between a

of

0000000

- 100V and between

of

1100.000; the 100µ,V,

and 1999999 full scale on

8).

at

a rate

1.

Stepping from

1.

The whole display

000000

and 199999

' . l

lmV

and lOmV

of

Range

of

Adjustment

for

AC

Functions

The l I t keys adjust the reading between a minimum

of009000 of

199999 full scale on 1

Ranges. The 1000V. Range has a Full Scale

1100.00; the

N.B.

There

(9%

ofNominal

lmV

is

no range

and

Range), and maximum

00m

V.....,... 1 00V

l0mV

of

ranges are truncated.

adjustment on Resistance

and Current

of

functions.

Leading Zeroes

For

fractional readings, a leading zero is presented to

of

the left except for

lm

the decimal point to emphasise its position,

O

and

UTPUT

1.

RANGE

selections

output terminals. AC

Voltage - an intemal short circuit is connected

across the output terminals.

DC

and

AC

Current - output terminals are opencircuited. On

n ranges in Remote Sense with

OUTPUT

ON,

the Zero key connects a true 4-wire intemal short circuit to the

With

Remote Sense

OUTPUT

is connected, but the actual resistive value

terminals as shown below.

LED

UNLIT,

the same short

of

this short may be calibrated ( See Section 8 and diagram below).

I+

DC ZERO and polarity. On DC voltage and current, a

is

polarity sign

present except

at

zero. The numerical

display represents the rriagnitude of the output.

. As the display value is stepped to zero, the polarity

sign disappears, and the opposite sign appears as stepping continues in the same direction.

0

UTPUT

is

O N

<luring

the sequence, the change in

If

the

output polarity is signalled by a changeover from one

polarity

N.B.

If

ON

the 4

LED

705

to the other.

is

in Offset Mode, with an offset

present, the display and output zeroes do not

coincide.

positive sign on the display, and the

LED

When using the

It

is therefore possible to have a

lit; and vice-versa.

+ I , keys or Zero key to obtain a

ON.:_

zero, the polarity is not changed over and the, same

OUTPUT

ON

LED

remains lit. The polarity

LEDs

change over only when the opposite polarity appears

at the output terminals.

Full Range Key

When the Full Range key reverts to the nominal value

OUTPUT

is

already

ON,

is

pressed,the display

of

the range selected.

Jf

the terminal value follows

the display value· unless: ·

·

1.

The combination of output voltage and frequency

would exceed the instrument' s intemally defined

limits. (Refer to Section 6).

Hi

I

'Remote

Deselection of Zero

The size significant. A half-size

'Zero

Sense'

in '

4705

True

4 - Wire

in

of

the characters on the 'Zero' display is

Ohms

Zero

AC Functions ·

·'O'

above any +

Lo

I-

14-w;:e

-~

Ohms

1,

key indicates that it cannot be used to desetect Zero, because it increments values which are less than 10%

of

nominal range.

Any

+ key with a full-size

'O'

above it ( and any key to its left) deselects Zero and adds its increment.

Selection of High Voltage Outputs

The 4

705

is capable

of

delivering

LETHAL

output voltages so program interlocks are used to ensure that users do not inadvertently select outputs in excess

of 1 I0V

in

DC

or 75V RMS in AC. Details of the High Voltage selection procedure are given in Section

4.

2.

Offset or Error Mode

off set or gain error

is

selected: the user-input

is

not cancelled from the

output.

Zero key

This reduces the display value to zero. is

ON, the terminal value

DC

Voltage - an active zero

is

also set to zero:

is

presented to the

If

OUTPUT

Frequency

The

AC

voltage output of the 4705 extends from

0Hz

to 1

MHz

in

five

1

a resolution of 1 %

five

Any

frequency values within the range

overlapping decade ranges, at

of

nominal Frequency Range.

instrument can be stored in volatile memory.

of

the

3-5

FREQUENCY RANGE keys

Auto-1 ncrement/ Decrement

When a +

digit is increased or decreased approximately 3 digits per second until the key is released.

Overflow and Underflow

As a digit is stepped from 9 to 0, the value ofthe next higher-order digit 0 to 9 decreases the value by therefore acts as a counter, with full 'carry' and 'borrow' action.

1,

key is pressed for more than ½ second its

at

a rate of

is

increased by

1.

Stepping from

1.

The whole display

Guard Sense Spec Error Offset Test

- Remote -

Decade Ranging

Generally, selection frequency by a whole number ranging-up from a frequency -between lOHz and 30Hz, or ranging-up to the decade frequency would have been higher, causes

Error 7 to be displayed and buzzer to sound.

Selection of Nominal Range Value

Once a Frequency Range has been selected, it can be set to its nominal value by re-pressing its key.

FREQUENCY DISPLAY

STO

SET

MODE

of

a new range changes the

MODE FREQUENCY

/

I •

±0

l00kHz

/7

LI

LI"'

of

range when the

GAL

decades; but

k

Autoranging

Stepping the frequency beyond the span automatically switches range up or down, but further steps are inhibited until the • or

_ key could be below a decimal point). When the

range-change occurs, the alarm buzzer sounds and

FREQUENCY display is blanked for

the approx. 1 second.

is

When the display remembered the last frequency on the old range, and sets the new range to its next incremental frequency in the original direction. After releasing the original key, stepping-can be continued to any increments the new range.

Autorange Limits

The 4705 displays an Error 7 and sounds its buzzer when any attempted frequency increment or decrement is made which would produce an invalid

of

combination or FREQUENCY. Neither will it incremen'.t or decrement to a frequency beyond the limits next frequency range up or down.

FUNCTION, OUTPUT RANGE

reinstated, the 4

t key is released ( the

of

a range

705

of

has

of

the

Il

Resolution

The output frequency the selected FREQUENCY RANGE nominal value, matching the display resolution. Legends are appended on the display as appropriate, leading zero is presented to the left of the decimal point for fractional values.

FREQUENCY t lf Control

Each vertical pair display digit above

is

the display Each momentary press of the • key adds 1 to its digit, and each output frequency increments as the display ( subject to the instrument

interlocks inactive. ,

adjusted by manipulation ofthese keys.

t key subtracts

).

Keys below decimal points are

is

adjustable in steps of 1 %

Keys

of

+

1,

keys

is

assigned to the

it.

The frequency registered on

1.

If

OUTPUT

is

also changed by the same

is

ON, the

of

å.nd

3-6

a

_ combinations

· selected.

OUTPUT/FREQUENCY

AC Voltage and Frequency

Under most conditions, the output amplitude and

frequency are adjustable throughout their full

scales:

Voltages - from Frequencies - from lOHz to

On

the

l00V

of

voltage and frequency cannot be

The diagram below illustrates the boundaries. The 1 comparison. The combination outside these constraints. The temporary message approximately 1 second before reverting to the original display.

0V

Range span is also shown for

4

705

refuses to select any Voltage/Frequency

CONSTRAINTS

90µ,V

to 1100V RMS

lO0kHz.

and 1000V Ranges, certain

Error 7

is

displayed for

AC Current and Frequency ·

AC

Current RMS at frequencies from 1 Ranges have the same span).

is

adjustable between 9µA and

0Hz

to 5 kHz ( all Current

Error 7 indicates an

invalid Current/Frequency selection.

2A

MODE FREOUENCY

1=2

IDL7

~

k

FREQUENCY

This facility allows storage

MEMORY

ofup

to

five

user-selected frequencies. Ortce stored, each can easily be retrieved or changed from the front panel. They are retained until power is removed from the instrument or

reset key

is

depressed.

Store Key

Only

five

of the FREQUENCY RANGE keys

select ranges. The first press reassigns the other

five

ofthe

sixth key, Store,

as frequency memories. It

has toggle action: a second press deselects the memory function.

1000V

Output

Voltage

(Log. Scale)

Frequency

Range

110

Spans

100Hz Range

1kHz Range

I 300 3.3k I

330 I

10kHz Range

!

3k

DANGER

HIGH VOLTAGE

~&

I+

I·

Guard

®®®

~~,

100kHz Range

I

3ok

10Dkl

33kHz

I

Guard Sense Spec Error Oflset Test

-

Remote-

sro

sr,

±o

MODE

1000V Range

(1

OOkHz

not

selectable)

1100V

Range

C.At

200V

100V

20V

10V

1V

200V

SOV

------------'

9V

(Lower

100V Range

20V

10V Range

Ranges

also

cover

the

full

frequency

span)

0.9V

Voltage

Range Spans

45Hz

I

10

30

I· I

100 300

Output

1k

Frequency

I I

3k

(Hz) (Log. Scale)

10k 100k

100kHz

.1

3-7

F 1-

F5

M emory keys

When the Store

LED

is

ON, these keys select

individual memory locatiorts.

N.B.' Although the

FREQUENCY

RANGE

keys double as memory selectors, this does not imply that a particular memory can only accept frequencies from its key' s range.

It

is

emphasized that any displayable frequency

can be stored in any of the

Power-up Default

five

locations.

Because the stores are volatile, the following default frequencies are stored in the each time the

4705

is

five

memory locations

powered-up:

CALIBRA

press cancels the function.

TION

INTERVALselection. A second

For

24-hour calibration

intervals, the 'accuracy relative to calibration standards' figures are displayed but for

90

days and

1 year intervals they are 'Traceable' accuracy

figures which include Datron's Calibration

Uncertainty.

CALIBRATION INTERVAL

90dy

'24hr~1yr

Fl F2 F3 3kHz F4

F5

Details described

MODE

30Hz

300Hz 30kHz

lOOkHz

of

storage and retrieval procedures are

in

Section

Selection Keys

FREQUENCY RANGE

Store 100

4.

1k

10k 100k

0

Guard Sense Spec Error Offset

Remote -

STO

MODE

SET

±0

Rear Panel CALIBRATION INTERVAL switch

While in S pec mode, all primary functions other

MODE

keys are cancelled (although the

of

the

selected Guard and Sense connections remain). The

keys are reassigned to their secondary functions:

+ lim,

Spec mode

-lim,

% and ppm become active. When

is

initiated, the magnitude

of

the

specification tolerance itself determines whether

ppm or %

is

selected. The arrow .,_... above the S pec

· key shows that all four secondary modes are available.

Full details are given

ERROR

in

AND

the operation

Section

OFFSET

4.

of

MODES

Specification mode

of

These keys are used to deviate the output at the

terminals from the value on the

OUTPUT

display.

The two modes may be selected together.

Error and Offset Modes

The terminal value ·

OUTPUT

DISPLAY

NOT

Selected

is

a linear function of the

value:

The

MODE

left

of

Remote Sense keys are described under

Lo, Guard and

STD, SET, +o and CAL are calibration modes,

printed

SPEC

MODE

selection keys are located on the lower

the front panel. The Remote Guard and

'I+,

I-,

Hi,

~

in

red and described

in

Section

8.

The S pec key controls the toggle-action 'Specification' function. By pressing the key, the

4

705

specification tolerances are display ed on the

MODE

FUNCTION,

display, referred to its current

OUTPUT,

FREQUENCY

and

3-8

Terminal Values+

+

OUTPUT display values

Error mode selected

Terminal Values +

~

±10%

~

displayed

Value

of

Terminal Values+

+

OUTPUT display values

Full details in

~ection 4.

of

the operation

of

Error mode are given

Offset mode selected {DC Functions only)

In

Offset mode, the intercept ( c) may be adjusted to

any value within the Offset limit. Offset Limits: 100µ,V and

Other Ranges:

lmV

Ranges: +200µ,V.

+2%

of

Full Range

value.,

·Terminal Values+

offset selected-

TEST

MODE

Test mode selected

Full details in Section

1+,

1-,

4.

Hi,

ofthe

operations in Test mode are given

Lo,

Guard

and~

(Ground) Terminals ·

Local and Remote Switching

MODE FREQUENCY

not

selected +

OUTPUT display values

selected

+.

Output

display

values

Offset and Error

Mode

Combination.

Offset cannot be selected or deselected when the

4 705

is

already

The intercept ( then the slope (m)

Full details combined mode are given

in

Error

c)

is

established first

is

of

the operation

Mode.

adjusted

of

in

Offset mode,

in

Error

mode.

Error, Offset and the

Section

4.

DANGER

HIGH VOL TAGE

~&

I+

I·

Guard

®®®

FREQUENCY RANGE

Store 100

121aaaaa

-

+-hm

1999t51199

Guard Sense Spec Error

-

-lim

Remote-

F1

F2 F3 F4

,..___.

",JIJ

MODE

1k

10k 100k

---

-..r

r

0

Olls~I

FS

o

ppm

Test

These terminals are located on the lower left of the

Front Panel.

1+

and I-Terminals

The output from the interna! power circuits

· delivered to the

I+

terminal, I-being its Return

Analog Common.

Hi and

Lo

Terminals

These terminals provide a differential input to the amplitude sensing circuitry.

is

3-9

Remote Sense

The Remote Sense key has 'toggle' action.

Successive presses altemate between

OFF. ' N.B. Sense connections can only be switched

with OUTPUT OFF.

ON

and

For

Voltage outputs

should be attached to the Hi and Lo terminals.

Various configurations of detailed

in

Section

in

local sense the two leads

4

705

load connections are

4.

The specified voltage output

produced either at its output terminals (Local Sense for high impedance loads) or at the load terminals (Remote Sense for cases in which lead resistance

and load impedance produce a significant effect).

With Remote Sense OFF, the isolated, and the voltage output

terminal. · With Remote Sense ON, the output voltage

across the sensed extemally, using leads connected to the and Lo terminals. ·

Remote Sense

ranges. On Ohms ranges, Local Sense

connections, and· Remote Sense for 4-wire. (Changing FUNCTION into Remote Sen se, hut this may be deselected for 2-wire operation). The Remote Sense indicates the true connection:

Lit

I+

and I - terminals only, and must be

is

not available on lO0µV - lO0mV

It

is

not applicable to Current outputs.

= Remote; U nlit = Local. .

of

the 4

705

may be

I+

terminal

is

fed to the

is

used for 2-wire

is

Hi

fed

Hi

n forces the 4705 into

LED

always

Guard Terminal

The Guard terminal

interna! guard shields:

Remote Guard

The Remote Guard key has 'toggle' action. Successive presses altemate between

OFF.

With Remote Guard OFF, Guard connected to the I - terminal.

With Remote Guard ON, the interna! link to

is

removed. The . Guard terminal can then be

connected extemally to reduce common mode

interference.

Ground Terminal

The

-:-

( Ground) terminal connects directly to the

4

705

in.tema! Ground shields and to Safety Ground

via the power-cable.

Output Connections

Connections to the output terminals may be made

either with leads or via a shrouded connector.

3-10

is

permanently connected to the

ON

is

intemally

and

I-

Rear Panel

(Shown with alternative Rear Output terminals).

r/

u

..._

-----

MODEL SERIAL

No

RtNEW

BATT

AT

TS

See

INPUT VDL FREOUENCY 48-62Hz POWER 400VA OPTIONS

POWER

INPUT

IJr&J

Power

Approx

POWER FUSE

11

D

lnput

,,,

J27

IEEE

488

~,-

CALIBRATION

INTERVAL

90<1y

24hr

CALIBRATION

ENABLE

*

""~

7~

1 yr

SH1AH1T6 TE0L4LE0' SR1RL2PPIJ' DClDT~C~El

•

S53

lllllllCJ

OFF

DN

J53

0

-----

rJ

w.-.-:;

7 r

\..

DANGER HIGH VOL

....

;

~i~

TAGE

_&

~

j)

i i

'

.,

L

~

-

"'-

)

~

POWER

INPUT

The recessed POWER INPUT plug, POWER

FUSE

located in the center within a single moulded unit. Details selection ofline voltage and

REAR

and LINE VOLTAGE SELECTOR are

'Of

the rear panel, contained

of

connections,

fuse

are given in Section

OUTPUT

ALTERNATIVE (Option 42)

2.

This can be incorporated at manufacture, to provide six output terminals on the rear panel instead of the six on the front. Their functions and connections are identical.

SOCKET

(Externa! Reference Frequency lnput)

['-..

J53

This BN C socket is located next to the cooling air

It

intake filter.

may be used to lock the internal frequency synthesizer to a customer' s own frequency standard. Voltage and frequency criteria are given in Section located above this socket facility. is

Ifthe

switch

not present, error message 'Error EF' is

2.

An

on-off switch; S53,

is

provided to enable this

is

on and an external frequency

displayed.

SOCKET

The

J27

{IEEE

IEEE

488 Input/Output(D-type) socketJ27

488

lnput/Output)

a 24-way micro-ribbon connector that

compatible with the

IEEE

48 8 interface and the

IEC-defined system.

· 127

is

located at the top

with the

IEEE

488 address switch. The pin layout

of

the rear panel, outlined

and designations appear in Sections 2 and 5.

IEEE

488

ADD

The 4 IEEE

ADDRESS

5 4 3 2 1

705

may be addressed for use on the

48 8 interface bus. The address settings are

SWITCH

given in Section 5.

is

directly

'O'

. '1'

)-]t

is

SOCKET

This D-type socket

J54

(Externa! Reset)

is

located next to the optional rear output connectors. It may be used to input an external reset to restore the

4705 to its power-up

state of DCV, 1 V Range etc. ifrequired. Pin Layout, Pin Designation and Switch Wiring details are given in

Section

2.

3-11

I

r

THIS

...

HIGH VOLTAGE

INSTRUMENT

OF DELIVERING

A

llTHAl

DANGIR

IS CAPABLE

lllCTRIC

SHDCK

&1

-~

!

r

..

Unless

it

DO

I+

NOT

I-

and

Guard terminal is sensitive voltage

It

can

_

your

you

is safe

instrument!

are sure

to

TOUCH

Hi

or

Lo leads

terminals

to

over -

damage

that

do

so,

the

·

3-12

DANGIR

-

_:-_-

-- - -----. ---~-·

·---~·

·----:-·---··----~

--~·::_-~--:--:--:--=-:s::..:.:··---·~---

---~-~-

..

-.·__:_-.--.~---·-··-~-.:___:...:.-~---~-----

,.c..-·

SECTION 4

USING

THE DATRON

Preliminaries

Before using the instrument it is important that it has been correctly installed as detailed in Section 2.

Limiting Characteristics

The following details are given in Section

Function

All functions DC

Voltage

AC

Voltage

DC

Current Maximum load resistance and

AC

Current

Resistarice

Characteristics

Peak terminal voltages Output · resistance and current limit Output resistance and current

limit; capacitive loading limits

maximum compliance Maximum load resistance and

maximum compliance

Maximum currents and accuracy

de-rating factors

6:

4705

UNDER USERS TOUCH ANY OF THE FRONT (OR REAR) PANEL TERMINALS UNLESS THEY ARE FIRST SATISFIED THAT NO DANGEROUS VOLTAGE IS PRESENT.

CAUTION: THE

THE DETAILED IN THIS PLACED ADJACENT THAT ARE SENSITIVE CONDITIONS.

REFER

I nterconnections

IMPORTANCE OF CORRECT CONNEC!IONS

NO CIRCUMSTANCES

A SYMBOL IS

USER

OF SPECIAL PRECAUTIONS

USED

HANDBOOK

TO

SECTION 6.

SHOULD

TO

REMIND

AND

TO

TERMINALS

OVERVOLTAGE

IS

-

'j

The

4

705

is

designed to be Class 1 equipment as defined in concerning safety requirements.

Protection is provided by a direct connection via the power cable from ground to exposed metal parts and interna! ground

The line connection must only be inserted in a socket 6btlet provided with a protective ground contact, and continuity

between the socket and the instrument.

IEC

Publication 348 and

screens_.

of

the ground conductor must be assured

UL

1244,

WARNING:

ANY INTERRUPTION OF THE PROTECTIVE

GROUND

CONDUCTOR

INSIDE

OR OUTSIDE THE INSTRUMENT, OR DISCONNECTION OF THE PROTECTIVE GROUND

TERMINAL MAY MAKE THE APPARATUS DANGEROUS. INTENTIONAL INTERRUPTION IS PROHIBITED.

THE TERMINALS MARKED WITH THE

~

SYMBOL CARRY THE OUTPUT OF

THE 4705. THESE TERMINALS

TÖ

OTHER CONNECTIONS UNDER

TEST COULD CARRY LETHAL

THE LOAD

AND

ANY

VOLTAGES.

The 4705 has been designed for use as an accurate source for precision calibration. T o match the externa! circuitry to its superior specification, it is essential to take great care in making connections to the load.

SOURCES OF ERROR

Thermal

These can give rise to series (normal) mode interference, particularly for low voltage outputs,

and where large currents have a heating effect at thermo-electric junctions. Draughts can cause unbalanced cooling in an otherwise thermoelectrically balanced measuring circuit.

E-M

N oisy or intense electric, magnetic · and

electromagnetic effects in the vicinity can disturb the measurement circuit.

Some typical sources are:

- Proximity

- Fluorescent lighting.

- Inadequate screening, filtering or grounding of

- Transients from local switching.

- Induction · and radiation fields of . local

- Excessive common mode voltages between

EMFs

I nterference

of

large electric fields.

power lines.

E-M transmitters. source and load.

4-1

----------------------------------11111!!!1111--

The disturbances may be magnified by the user' s hand capacitance. Electrical interference has greatest effect Separation

of

in

high . impedance circuits.

leads and creation of loops

in

the

circuit can intensify the disturbances.

Lead I mpedance

The impedance

of

the connecting leads can drop significant voltages between the source and load, and generate adverse phasing effects particularly if the leads · are long or the current in them

Lead lnsulation Leakage

is

high.

This can cause significant errors in measurement circuits at high voltages. Some insulating materials suffer greater losses than others e.g. PVC has more leakage than

A,.VOIDANCE

Thermal

PTFE.

TACTICS

EMFs

Screen thermal junctions from draughts.

Allow time for thermal equilibrium to be reached before taking readings. U se conductors, joints and terminals with a good margin

of

current-carrying capacity.

A void thermo-electric junctions where possible:

e.gi

Use untinned single-strand copper wire

of

high purity. Avoid making connections through Nickel, Tin, Brass and Aluminium. oxidation

is

a problem use gold-plated copper

If

terminals, and replace the terminals before the plating wears

off.

Ifjoints must be soldered,

lowthermal solders are available, but crimped joints are preferred. U se low-thermal switches and relays where they form part of the

measuring circuits.

Balance one thermal

EMF

against another in opposition, where possible, ( switch and relay contacts, terminals etc.)

r'\

E-M

"

I nterference

Choose as 'quiet' a site as possible ( a screened cage may be necessary if interference

is

heavy).

Suppress as many sources as possible.

Always keep interconnecting leads as short as possible, especially unscreened lengths. Run leads together as twisted pairs in a common screen to reduce loop pick-up area, but beware of leakage problems and excessive capacitance. Where both source and load are floating, connect

1-

to ground at the source to reduce common mode voltages.'

at the

load~

Use ·4-wire connections for values

of

resistance below 1 kO.

Lead lnsulation Leakage

Choose low-loss insulated leads -

PTFE

is preferred to PVC. When running leads together in screened pairs, avoid large voltages between leads in the same screen, especially if using PVC insulation.

Remote/Local Sense Cor:,figurations

The 4

705

terminals are configured as follows:

Voltage ranges

lOOµV,

lmV, lOmV,

lOOmV

- Local sense only. lV,

lOV,

lOOV,

- user selects ·Local or

1000V

Re_mote

sense.

All Current ranges

- Local sense only.

All Resistance ranges

- Remote -Sense gives 4-wire

connection.

- Local Sense provides 2-wire

connection capability.

The key

N.B. When changing to O function, the

LED

indicates the true connection:

Lit=

Remote, Unlit = Local.

4705

is

automatically forced into Remote Sense for

4-wire operation.

4705 -CONNECTIONS

General Considerations

The choice

of

connection method

TO THE LOAD

is

influenced by

several factors:

a.

Loading Effects

4-wire connections should be used for low load impedances.

For

high impedance loads, 2-wire

connections can be employed. The ratio : Total Lead Resistance

Load Resistance

gives the approximate error for 2-wire connection at low frequencies. e.g. Two ½-Ohm leads with a load produce an error of approx. 1

of 1 OOkOhms

Oppm.

Il

I

Lead I mpedance

Keep all leads as short as possible. U se conductors with a good margin

of

current-carrying capacity. U

se

Remote Sense and 4-wire connections where

necessary to establish the

4

705

output specification

4-2

b.

Noise and Output Level

Providing the

E-M

environment

is

reasonably quiet, interf erence due to noise pickup in the load connection

is

insignificant for outputs of more

than about 100m

V,

so unscreened leads can be

used. But at lower signal levels, or in noisier

environments, it

is

advisable to use screened

cable.

c.

Common

Mode

Disturbances

When in Local Guard, the guard shields and tracks for the Sense circuitry are connected intemally to the 4

705

'I-',

the low impedance terminal

output power source. This classical connection effectively guards out intemal common mode disturbances. disturbances it

is

advisable to make only one

To

reduce extemal

ground connection to the measurement circuit,

and in the case

of

a guarded D

MM,

to make use its externa! guard facilities. Also, where a linepowered load (such as a

DMM

being calibrated) has a ground connection, it should be to the same line ground as the

d.

High Frequency Effects

i.

Voltage. Up to lO0kHz,

is

it possible to use pairs

provided

thatthe

4

705.

for

outputs above 100m

of

unscreened wires,

E-M.environment is quient. Twist

or run leads together; keep length less than 1 meter.

of

Setting Priorities

Because a.

the variety of environmental conditions and loads

of:

likely to be ,encountered when using the

b.

the extensive set

of

combinations

of

outputs from

the instrument, and

c.

the accuracy required;

it

is

unrealistic to describe a definitive 'best' general

of

method Combinations

connection to the load.

of

the above factors can lead to conflicting requirements, and users may be faced with a choice between methods. In these cases it

sometimes necessary to arrive at a compromise solution by setting priorities.

Suggested Lead Connections for the

Six suggestions for connecting the 4

4705

705

are illustrated in the following pages 4-4 and 4-5. Each

has found use with the combination described, and together they cover the majority predicted requirements.

V,

4705,

is

to its load

of

factors

of

ii. Current. Above about

lkHz,

with low output currents, high lead capacitance can introduce shunt errors.

To

reduce these errors, the leads should be kept as short as possible, and be of lowcapacitance.

e. DANGER.

THE 4705 OUTPUT CIRCUITS ARE NOT INTERN ALL Y CONNECTED

'\

GROUND. USERS ARE STRONGLY

TO

ADVISED

,EXTERNALLY

(PREFERABLY

JUNCTION),

USED THIS AND

ON

THE

ELIMINATES

I-

CONNECT Lo OR

TO

AT

THEIR COMMON

WHEN

FLOATING

IO0V

THE

OR

THE

4705

IO00V

RISK

TO

GROUND

IS

RANGE.

VOLTAGE.

TO

1-

TO

BE

OF

HIGH

Lo

4-3

Typical Lead Connections

Voltage and Resistance Outputs

CAUTION: All leads and cables must be proofed

to ·at least 2kV.

Simple

Use for many applications where:

The voltage drop in the leads The Extemal common-mode voltages are insignificant.

U se for measurements in the following ranges:

N.B.

Select Local Sense and Local Guard. Keep leads as short as possible, ( not longer than 1 meter-twisted pair

On 100V

2-wire

E-M

Voltage Frequency F

Resistance

After selecting

Connection

environment

DCV ACV

< 1 00kHz

lkO

is

'quiet'.

> 1 00m V > lO0mV

< R <

n,

Remote Sense must be

cancelled for 2-wire operation.

is

preferable).

/lO00V

Ranges, Ground the Lo line for Safety.

is

insignificant.

lMO

Note: Refer also to reactive load specifications m

Section 6.

@ @

I+

4705

Terminals

Load

Terminals

_______________

~~----0

Hi

I-

Lo

/@

/ Gu Local Guard

/ Local

Gu Local Guard

Sense

_

Screened

2-wire

Connection

Use where:

Sensitive measurements are being made.

. The

E-M

environment

is

relatively 'noise'.

Extemal common-mode voltages are significant.

U se for measurements in the following ranges:

Voltage Frequency F

Resistance 1

After selecting

DCV

;>

lOµV

ACV

> 90 µV

< 1

OOkHz

kO

< R < 1

n,

Remote Sense must be cancelled

MO

for 2-wire operation.·

Select Local Sense and Local Guard. Keep leads as short as possible, ( not longer than 1 meter).

On 100V/1000V Ranges, Ground the Lo line for Safety.

S~reened

4-wire

Connection using Coaxial cable.

Use where: ·

is

The load resistance significant voltage drop

low enough to cause a

in

the output

connection.

Sensitive measurements are being made.

The E-M environment

is

relatively noisy.

4705

Externa! common-mode voltages are significant.

U se

for

measurements in the following ranges:

DCV ACV

<

> 90m V

;>

90mV

lOOkHz

Voltage

Frequency F Resistance Not appropriate

Select Remote Sense and Local Guard. Keep leads

as

short as possible, ( not longer than

1 meter).

On 100V /lO00V Ranges, Ground the Lo line for Safety.

@ @

4705

Terminals

Load

Terminals

________________

Terminals

Load

Terminals

________________

I+

Hi

I-

Lo

/@

/ Gu

/

~

Gu

":'

Gu R,emote Guard

Local Guard

Sense

Local

Optional

Remote Guard

_

Local Guard

Sense

Remote

Optional

_

4-4

]1

Typical (Cont'd)

]]

.,

Lead Connections

~•

i

--------·-

Voltage and Resistance Outputs ( cont'

]I

, Screened

Alternative using Twin-axial cable.

On 100V/1000V Ranges, Ground the Lo line for Safety.

]l

4-wire

Connection.

11

JI

Current Outputs

JI

Simple 2-wire Connection

U se for the majority

The

E-M

JI

]

JI

]

Externa! common-mode is insignificant.

U se for measurements in the following ranges:

Current

Frequency F

Local Sense selected automatically. Select Local Guard. Keep leads as short as possible, ( not longer than

1 met~r - twisted pair is preferable).

environment

of

applications where:

is

'quiet'.

DCI

> 1

mA

ACI

> lOOmA

< 5kHz

d)

4705

Terminals

Load Terminals

Note: Refer also to reactive load specifications in

Section

6.

4705

Terminals

Load

Terminals

Hi

I+

Lo

I-

Gu

Local Guard

]I

Screened

Use where:

Sensitive measurements are being made. The1 Externa! common-mode is significant.

U se for measurements in the following ranges: Curren.t

Frequency F < 5kHz

Local Sense selected automatically. Select Local Guard. . Keep leads as short as possible, ( not longer than

1 meter - Co-ax. or Twin-ax.

2-wire

E-M

environment

Connection

is

DCI

> 9

µA

ACI > 9µA

relatively 'noisy'.

is

preferable

).

4705

Terminals

Load

Terminals

®

Hi

t+

®

Lo

I-

Gu

Remote Guard

4-5

General Sequence

DANGER

HIGH VOLTAGE

~Li\

@«!>i

of

Operations

@aäåäa

-F1

F2 F3 F4

FS

~~,

1gggg99

Gua,d

Sense

Spec

Error

Sto

MODE

orrse1

sr,

!O

-Remo1e-

Display Messages

( See

full

list at end of this section)

Error 1 : Spec. mode - % : Uncertainty

- + lim : Off-scale limit.

Error 2

Error 3

Error 4

Error 5

Error 6 Error 7

Error 8

Error 9

: Cal. mode : Cal. mode.

: Cal. mode

: Offset or

Error mode : Cal. mode : 100V/1000V: Selected output exceeds

: Select error : The operation requested by

: Option not

fitted.

Output not ON. Incorrect range or function

for mode.

Correction exceeds· store capacity.

Requested output would have been off-scale.

Resistance exceeded.

voltage/frequency constraint.

the user

is

not possible in

present machine configuration. SAFEtY Forced safety watchdog trip. The requested range or

function option

Tes1

C~t

> 100%

is

not fitted.

Error

EF

: Extemal : The extemal frequency is not

will

perf orm

Error

FAIL FAIL2 FAIL FAIL4 FAIL5 FAIL6 FAIL7

frequency present, machine

of

out

OL:

1

Voltage

Current

Excessive intemal temperature.

Output is current-limited. Compliance limit reached.

Over-voltage.

3

Control data corrupted. Precision divider fault. Safety circuits tripped. Calibration store fault. 400V power supply overload.

specification.

Automatically resets except where

hard fault occurs. FAIL8 FAIL9

'B'

t

mode messages:

TeS

38V power supply overload. 15V in-guard power supply overload.

Processor busy

(keyboard unreceptive

).

r,unning lndicates test in progress.

PASS Calibration memory, over-voltage

deiector and 400V switching checked.

4-6

I

Operating Routines

The following operating routines are subdivided into two main types:

• Standard Operating Sequences

• Additional F acilities

Standard Operating Sequences

There are routines for both V oltage and Current operation. The diagram opposite shows the gener,al sequence of operations.

· operating procedure, in c.onjunction with the individual selections detailed in the following pages.

DC

There are two overlapping voltage states. The 20V overlap allows full range value

many

Voltage Outputs

common elements

It

should be used as the basis

+ 10% adjustment·about the typical

of 1 OOV

±90V

Low voltage

in

the selection

without changing state.

±110V

state

of

any

Transfer into High Voltage

By changing RAN

GE:

- the OUTPUT selected RANGE

State

with

OUTPUT

is

switched OFF, and the

LED

flashes.

User reselects OUTPUT ON:

- 3 sec audible warning

-

4705

switches OUTPUT~ON

- Audible reminder whilst OUTPUT

-

RANGE

By use

of

- 0 UTPUT remains O N at previous volta

-

9UTPUT

LED

flashing.

+It

keys in 1 00V or i 000V range:

display shows selected (High

ON

Voltage) value

-

RANGE

and OUTPUT

ON

LEDs

flash.

User reselects OUTPUT ON:

- 3 sec audible warning

-

4705

increases OUTPUT voltage to

OUTPUT display value

- Audibl~ reminder whilst in High V oltage state

RANGE

- OUTPUT

LED

ON

flashing

LED

lit continuously

ON

ge

High voltage

In

the Low voltage state, the output may be switched

ON

directly but to transfer from Low to High

state

Voltage state, deliberate user-actions are required.

N.B. The

Low Voltage selections (up to

4705

switches its output voltage

every time the 1000V

when 1000V

RANGE

polarity

+HOV).

is

selected and

is

reversed.

Use the

OFF

general sequence:

At

operation@ : Select DC.

At

operations@ and ~ :

100µ;

lm,

10m

and

High Voltage selections (above

No

Remote Sense on

100m ranges

+HOV).

Use the

general sequence:

At

operation®

At

operation® : RANGE

At

operation @ : Audible warning - 5 pulses/

: Select

DC

LED

selections above

flashes for

±

11

0V

sec for 3 secs.

After

3 second warning

4

705

switches

OUTPUTON.

Whilst OUTPUT approx. 1 sec. intervals, and

ON

-Audible

reminder pulses at

RANGE

LED

continues flashing.

lf

OUTPUT

<luring

the 3 sec. delay the 4

OFF

or

ON

switching

705

reverts to OUTPUT

is

attempted

OFF.

Transfer out of High Voltage state

with

OUTPUT

ON By pressing OUTPUT

ON+

0 UTPUT Voltage has decayed into Low Voltage

or

'ON-

OFF

LED

key:

remains lit until the

State (Approx. 1 sec from 1000V).

By use

of

+ I y keys or by changing

RANG

E

down:

is

Transfer to Low Voltage State

automatic when

the OUTPUT Voltage falls below 90V.

-

RANG E LED

- OUTPUT

- Audible reminder

Changing voltage state

Mode

For

safety reasons, the thresholds are always

defined with respect to voltage levels OUTPUT terminals. Therefore, in

Error or Offset mode, the threshold indications

stops flashing - stays lit

ON

LED

stays lit

is

silent.

when

in Error or Offset

ifthe

at

instrument

the

is

may not coincide with 110V and 90V on the OUTPUT display.

AC Voltage Outputs

Zero Output

Zero

AC

Voltage output from the 4

705

can be

obtained only by pressing the Zero key. Interna}

I+

to

I-,

and

Hi

relay contacts short

to Lo.

4-7

I ncrement from Zero

The small est A C output available on any range 9%

of

full

range, so any attempt to reduce the output below 9% increment from Zero the appropriate key ( any key to the right

is

refused. Thus the smallest possible

is

to 10%

of

full range, using

of

this would

is

attempt to increment to 1 % or less, and be refused, causing 'Error

8'

and buzzer to sound). Half-size zeroes on the Zero display show which keys cannot be used · to increment from Zero; full-size zeroes show those which can.

When the display

0 UTPUT · 0

N,.

is

cprrectly incremented with ·

the output terminals are intemally

reconnected to the voltage output circuitry.

Zero Displays

Range

lmV

lOmV

lOOmV

IV

IOV

lOOV

C 1000V

Zero Display

. 0 0

0,

0 . 0 0

0,

0 0 . 0 0

. 0 0

o,

0 0

0 . 0 0

0,0

0 0 . 0 0

Ooo.oo

0,

High voltage selections (above

Using the general sequence:

At

operation ®: Select

At

operation

@:

OUTPUT

AC

75Y

RMS).

~ANGE

LED

· flashes for selections above 75V RMS.

At

operation @ : Audible warning -

5 pulses/sec for 3 secs.

After 3 sec.

While OUTPUT is

warning

ON:

: 4705 sets OUTPUT ON.

Audible reminder pulses

continue at approx. 1 sec. iqtervals, and RANGE LED

continues flashing.

If

OUTPUT

<luring

the 3 sec. delay the 4 705 reverts to O UTPUT

OFF

OR

ON

switching

is

attempted

OFF.

OUTPUT

If

OUTPUT

ON

Transfers

is

already switched

ON

in Low Voltage State when an attempt is made to select a voltage in excess

of

75V RMS, the 4705 safety interlocks

prevent the selection. Certain deliberate actions, detailed below, are then required by the operator to effect the selection.

m

lJ

[

[]

Output Voltage Selection

There are two overlapping

AC

voltage states. The

15V overlap allows some adjustment without

changing state.

60V

75V

I I

Low

Voltage State

High Voltage State

In the Low Voltage state, the output can be swhched

ON directly, but deliberate user-actions are required

to transfer from Low to High Voltage state.

N.B. The 4705 switches its output voltage

each time the 1000V RANGE

Low Voltage Selections (up to

Using the general sequence:

75V

is

RMS).

OFF

selected.

Transfer from

manual upranging:

Low

into High Voltage State, by

- 4705 switches OUTPUT OFF,

- Selected

RAN

GE

LED

flashes.

Operator reselects OUTPUT ON:

- 3 sec audible warning

- 4705 switches OUTPUT

- Audible reminder while OUTPUT

RANGE

~

OUTPUT

Transfer from Low into High Voltage State, by

incrementing the

- OUTPUT remains

LED

continues flashing.

ON

LED

OUTPUT

ON

lit continuously.

display:

at previous voltage

is

ON

- OUTPUT display shows selected value

- RANGE and OUTPUT

ON

LEDs

flash.

Operator reselects OUTPUT ON:

- J sec audible warning

- 4705 increases output voltage to the

OUTPUT display value

- Audible reminder while OUTPUT RANG E

- OUTPUT

LED

ON

flashing. LED

lit continuously.

is

ON

,.,,

At

operation ®: Select

At operations @)md @:

4-8

AC

No

lm,

ranges

Re~ote

Sense on

10m and 100m

Transfer from High into Low Voltage State, by pressing

-

ON

OUTPUT

LED

OFF key:

remains lit until the outputvoltage

has decayed (approx. 1 sec from lkV).

,,.

I

Transfer from High into Low Voltage State, by decrementing the downra11ging:

\

OUTPUT

display, or by manual

Transfer to Low Voltage State

is

automatic when the Output Voltage falls below 60V RMS.

RANGE OUTPUT

Audible reminder

Changing Voltage

For

safety reasons, the thresholds are always

defined with respect to the voltage terminals. When the instrument the displayed output voltage

LED

stops flashing - stays lit

ON

LED

stays lit

is

silent

State

when

in

Error

is

modified by the gain

Mode

at

the output

in Error mode

error, so the threshold indications may not

coincide exactly with 7 5V and 60V on the

OUTPUT display.

Frequency Control

Refer to pages 3-6 to 3-8.

DC

Current

U se the General Sequence:

Zero Displays

Ran~e

lOOµA

lmA

IOmA

lOOmA

lA

Current Outputs

To generate

AC

Zero Display

0 0

0,0

0 0

o,

0

0,0

0,

Oo.

0 0

0.

Oo.

. 0 0 o,o 0

output currents, use the General

Sequence:

At

operation®:

At

operations

select

@and®:

AC

followed by I.

N o Remote Sense.

N.B. Maximum compliance 3V on all ranges.

Changing functions switches OUTPUT OFF.

At

operation@

At

operations

: select

@and®:

DC

followed by I

Remote Sense not available

N.B. Maximum compliance 3V on all ranges.

AC Current

Zero Output

Zero

AC

Current output from the 4 705 can be

obtained by pressing the Zero key. This causes the interna! software to isolate the

I+

and I-terminals from the interna! circuitry, physically interrupting the Output Current.

lncrement from Zero

' The smallest

9%

of

full range, so any attempt to reduce the output

below

9%

increment from Zero

AC

output available on any range

is

refused. Thus the smallest possible

is

to 10%

of

föll range, using

the appropriate key ( any key to the right of this would

. attempt to increment to

1 % or less, and be refused).

Half-size, zeroes on the Zero display show which keys cannot be used to increment from Zero; fullsize zeroes show those which can.

When the display OUTPUT ON, the

is

correctly incremented with

I+

and

I-

terminals are internally reconnected to the Current output circuits.

is

Resistance

U se the General Sequence:

At

operation®

: Select n - Remote Sense

lights as 4 705 4-wire

At

operation@ : lf

2-wire Ohms

Remote Sense to deselect

At

operation@:

4-wire ·ohms - use

terminals for energizing current.

Measure at terminals. 2-wire Ohms - use Hi and Lo terminals.

(I+

and fused at terminals fused at function).

At

operation@:

RANGE key value OUTPUT display value

previously calibrated Range only, for 4-wire; at Full Range and Zero for 2-wire).

At

operation®

: Left hand ( overrange) pair. of + I y

keys have the same functions as Full Ran~e/Zero keys.

the other except (See Section 8).

LED

is

forced into

is

required, press

I+

and

Hi

and Lo

I-

terminals internally

l .0A, Hi and Lo

3.

7 5 mA; on n

is

nominal.

is

(At

Full

+ I y keys are inoperative

in

Calibration function

I-

as

4-9

Additional Facilities

Frequency Store

Store Key . ·

This key controls the storage and recall

selected frequencies. The memories are volatile in that their contents are lost when the 4 705 is powered-down. decade frequencies are stored automatlcally:

Fl F2 300f.lz

F3 3kHz

F4 30kHz

FS

ACCESS TO STORED FREQUENCIES

Recall a Stored Frequency

To

set the 4705 to one

simply;

Press and release the Store key.

- Its green

Press and release the desired

,_

Its

- The Store

- The stored frequency is presented on the

FREQUENCY

its store location ( see illustration). ·

~&

I+

@@@

At

30Hz

lOOkHz

LED

lights.

,-

r

DANGER

HIGH VOL TAGE

I·

Guard

power-up, the

ofthe

five stored frequencies,

lights.

Fl-FS

LED

remains lit.

display, accompanied by

MODE FREQUENCY

I I 7

-,

n117

,-

I I I

- - -

FREOUENCY RANGE

1ä8äEJåa

-

fo~lowing

F1

~ ~

of

five user-

key.

"\J

~

five

~

1ggggg~

~~,

Guard Sense Spec Error Offset Test

- Aemote -

'1

TIJ

MODE

'lf,

~r,

<,Al

Deselect Store

·

To

revert to normal frequency facility:

Press the Store key again.

LED

- Its

- The

---'

The

Re-program a Frequency

To

change the Frequency following procedure stores any · d1splayable frequency in any

Select the required Use the

Press and hold the Store key. Press and release the desired

display Release the Store key.

lf

STORE KEY -

Press and Release: Access

Press and Hold:

'Spec'

Spec Key

This key allows a user to avoid constantly referring

to

the data sheet specifications, when it

to determine the uncertainty for any set value.

Uncertainty Data Selection

The range

in interna! memory. Spec mode selects the stored data appropriate to the current settings

Range, Output Value, Frequency and Calibration Interval; then calculates and displays the overall

uncertainty.

FREQUENCY

the new frequency on display.

- Its green

- Its

~

The store location is also present on the

- Its desired, deselect Store as above.

Mode

of

goes out.

Fl-FS

stored rrequency · remains unchanged.

LED

4705 specification uncertainties is held

LED

goes out.

Memory

of

the five locations:

FREQUENCY

display

LED

lights.

remains lit.

SUMMARY

frequency retrieval. Allows displayed frequency to

be stored in

Store

a Memory

+It

Fl-FS

Fl-

FS

for stored-

of

_Store,

RANGE.

keys to set

key.

memories.

is

Function,

the

necessary

I I

Recall from a Different

To

switch to a different stored frequency:

Press and release the desired.

The displayed indications change as appropriate.

4-10

Memory

Fl-FS

key.

Initiation

To

transfer into Spec mode:

Select the required Calibration Interval

(Rea'r Panel switch).

Then follow the sequence in the diagram:

+Lim

To obtain a reading uncertainty:

or

-Lim

Press the

+Lim

or

of

an absolute limit

-Lim

key.

of

+lim

-lim

- - % ppm

•1111

Guard Sense Spec Error Offset Test

- Remote -

On pressing the Spec key the uncertainty appears on the

MODE

readout ( except for Store, Frequency cannot be

changed when in 'Spec' mode). Initially the

presentation

Uncertainty Display Units

STO

SET

±0

, MODE

display, displacing the Frequency

is

as shown in the following table:

CAL

< l ,999ppm of set value ppm

> 1,999ppm of set value %

Not

displayable or > 100% Error 1

MODE

The resolution as the will be the positive or negative absolute limit of uncertainty ( i.e. the the absolute uncertainty error limit for that output).

As the reading approaches full scale, its positive limit may exceed full scale.

Error 1

FUNCTION

The

OUTPUT

4705 will adjust its uncertainty figure appropriate to each new selection.

FREOUENCY

The

its 'Uncertainty' presentation. Consequently the use

of the

•

1,

Nevertheless, by pressing the

one

five

is

FUNCTION,

MODE/FREQUENCY

FREQUENCY

and Store keys

ofthe

'Stored' frequencies can still be accessed.

display will switch to the same

O

UTPUT

OUTPUT

display and its reading

reading plus or minus

If + lim is selecte.d,

displayed and the buzzer sounds.

and RANGE Control

OUTPUT

•1,

keys can be operated normally. The

MODE

Selection

Fl-F5

keys

in

RANGE,

is

inhibited.

BEFORE

in

Spec

Mode

RANGE

display to the

Spec

Mode

display

Store key followed by

is

assigned to

FREQUENCY

pressing Spec, all

and

Secondary Spec Modes

Once 'the Spec key has been pressed, the other

MODE

Jour

ppm, %, + lim, - lim.

ppm or % Uncertainty

From 1 ppm displayed in displayed the message sounds.

Example of Error 1 Condition (Any Cal interval)

Output range 1 V Setting Zero. key pressed. Frequency Any frequency. Uncertainty Mode display

keys become reassigned to give a choice of

display modes:

(of displayed value).

_to

l 999ppm, the uncertainty can be

ppm. From 0.001 % to 100%, it can be

in%.

When the uncertainty

Error 1

is

Error

is

displayed and the buzzer

Not

1.

is

not defined,

defined at Zero.

In

this case the the appropriate uncertainty figure. But a readout the Stored frequency can be obtained by merely pressing and releasing the

The store location and frequency will appear for

lit.

about 1 second, before changing back to · the uncertainty figure.

4705

'Spec' Data

Section 6 breaks down the specification into:

a)

Stability

b)

Accuracy relative to Standards

c)

Datron's Calibration Uncertainty.

The

CALIBRATION INTERVAL switch on the

rear panel

24hr, 90dy, and lyr.

is

labelled:

MODE

display normally presents

of

Fl-

F5 key whose

LED

4-11

is

-----:-::-··----;----··-=--·-·

. ·····

--,.--.--.·

The stored uncertainty data

and (

c)

above, as follows:

(b),

23°c

24hr: 90dy:

lyr:

(b) + (c), 23°C + 1 °C

+ (c), 23°C +

(b)

+ 1

is

selected from (b)

°c

l0°C

Thus the accuracy figures displayed for 90dy and

lyr

are traceab]e to National Standards.

In verifying the instrument' s specification on receipt

of a 4 705, users are able to display the 90-day limits to check against the instrument' s specified traceable .

'24

accuracy. After recalibration, the

hour interval' limits should be used to verify against the same standards used for calibration.

Refer to Section 7, Specification Verification,

C for

further information.

'Error' and 'Offset' Modes (Voltage and· Current Only)

The specification of a high accuracy D

MM

( and of

other electrical measuring equipment) relates its

display readings to its input values. A petfectly

calibrated

MM

would have an exact

1:

1

D

correspondence, and the specification lays down acceptable tolerances of deviation from this direct

is

relationship. Plotted as a · graph, the ideal case

45

straight line at

° through the origin. The

a

tolerances, plotted on the graph, enclose an area on both sides of this line.

Reading

Ideal

case

Linearity error - the slope of the line varies.

isa

(A common variation leg" at zero

).

"dog's

Each of these elements could cause large enough

of

deviations to place the instrument out

tolerance, sometimes a combination of elements ' being responsible.

The

"Error"

and "Offset" modes allow a user to deviate the output ofthe 4705 in specific ways, so as to identify directly the causes

of

excessive

deviation.

Error Key

The Error key is used to initiate Error mode. The 4 705 terminal value can then be deviated from the

OUTPUT display value, by known gain factors, as

entered on the

Error

Mode

MODE

Display

Pressing the Error key changes the

display.

MODE/

FREQUENCY display from 'Frequency' readout

to 'Error Mode' readout. The initial reading always '0.0 ppm', indicating

tl1at

the terminal value

has not yet been deviated.

.

MODE/FREQUENCY

The terminal value

OUTPUT display, by pressing the

MODE/FREQUENCY display. The gain

the compensation being applied

percentage or ppm

, with positive polarity for an increase

+I,

Keys

is

changed, without altering the

+It

keys beneath

is

displayed as a

ofthe

OUTPUT display value;

of

terminal

value, and negative for a decrease.

is

Limits

of

Tolerance

There are three major causes of deviation from the ideal case:

Zero offset

the line does not pass through the origin. Most DMMs have a front panel adjustment to correct this.

Gain error

the slope of the line

is

not

45

°

4-12

The gain-compensation factor has a maximum possible resolution of

(DCV).

Example of the use of "Error" mode

To measure the linearity

± 0.1 ppm

of

a

of

DMM,

Full Range

a user needs

to:

Remove any zero offset. Detect and measure any inherent gain error ratio

full

( usually from its response to a

range input).

Calculate compensating deviations for each of the inputs for the linearity measurement, based on the measured ratio,

and

Compensate each input to the

DMM

so that the

linearity errors may be measured.

In

"Error"

measured,

mode, once the .gain error has been

th~

4 705 automatically calculates and

u

applies the compensating deviation to all its outputs

on that range and function; whilst displaying both the

of

nominal ( uncompensated) value compensation ratio. Only if the linear, will each corresponding 4705

DMM

reading agree with the

OUTPUT

output and the

DMM

response is

display value.

In

the following sequence a D

linearity.

For

purposes

of

explanation, it is assumed

that linearity is correct, but the

error

of

+ 100 .0 ppm.

MM

DMM

is

checked for

has a gain

r (

~

17 17

u·u

1

ti,9

0·00000

+/O·ODDOO

'

4705

'

o.ooooov

r--,'.---,

0 0 0 B

-t--

0 0

.. _ __J

___J

,--

----..

IEJEJdtldBEi[j

>---

~

'---

-----<

[Ej~

___J

1gggggg

\,_

+ I ,-, ,-, ,-, I n

1gggggg

\,_

,-,

,_,

. u u

I I_/ ' I_/

,-,

;-,

,-,

'-'

1m;o,ggg

__J

'--

/_I

I

I_/

1ggggg

__J

'---

,-,

/_/

,_,

,-,

DMM

'

_J

DMM

V

_J

R:

fL

(

I I j

Ul?u?

:~~

+10.00000V

0 0 0 B

ll

+9.99900V

compensated = set + ( compensation x set

value value

IEJEJdtiEiBBH

>---

0 u

~[El~-

10V + (

-100ppm

rat10

-----<

x 10V

+ I

,-, ,-, ,-,

i-{

/ u . u u

'-'

1gggggg

value

DMM

,-,

'

/_/ /_/

1ggggg

R

4-13

The 4 705 output has now gain error of the will be compensated in the same ratio on this range · and function until either the ratio mode

is

deselected. The Mode display presents the

compensation ratio directly. Note that the compensation polarity

polarity, therefore the true output

displayed values; in this case + 10 .00000V lO0ppm = +9.99900V.

The linearity directly comparing its reading with the O UTPUT display settings.

e.g. at

Other linearity check values could be:

Nominal

+5V read voltages are

Check

Point

DMM.

of

the

on this range, both 4705 and

+5.00000V

+4.99500V

4705 set

Value

b_een

compensated for the

All selected output values

is

changed or Error

is

shown, not the error

is

the sum of both

DMM

may now be checked by

, although the terminal

DMM

Reading

DMM

Terminal

Voltages

'Offset'

Offset key

A device being checked against the 4705 (say a

DMM)

N evertheless, a user may wish to perform other measurements before removing the offset error. The 4705 "Offset" Mode is used for this purpose.

N.B. The

The value

sum ofthe OUTPUT display value and the

display offset value.

The following example generates an offset .of

-100µ,V

values ( unless the 4 705 would be driven

scale

Mode

(DC Functions only)

may have an inherent zero offset error.

MODE

action: increment or decrement continuously until the key

).

If

is

· released.

of

output at the 4 705 terminals

on the lOV range

a key

•

It

keys have an automatic

is

held pressed, the display will

is

now the

MODE

of a DMM,

for all set

off-

L

I . I

r

-0.5V +0.1 V +0.

+0.0lV

Full Scale Limiting. The OUTPUT display cannot

be raised to a value which sets its overrange digit to greater than cannotbe

N evertheless, a combination value and gain error could result in an off-scale value.. The 4 705 prevents this by rejecting any demand for an error-corrected Output Voltage in excess message on the the OUTPUT display.

· Deselection of Error

display, tums the green Error restores the 4705 gain factor to unity. Normally the mode it

is

RANGE.

-0.50000V lO000V

+0.0lO00V

1,

raised above

of

full scale. The user

MODE

is

deselected by repressing the Error key, but

also tumed off by changing FUNCTION or

-0.50000V +0.

lO000V

+0.0lO00V

and the Error

+9.9999%

of

is

informed by Error 5

display with no change to

Mode

clears the

-0.49995V +0.09999V +0.00999V

MODE

(+999.9

O UTPUT display

LED

display

ppm).

MODE

OFF

and

Connect the range, ensuring that 4 705 Error and Offset

are UNLIT.

Note that the negative polarity

shown on the Output voltage OUTPUT displayed, not the polarity error.

DMM

display, i.e. the 4705 offset polarity

to the 4705, both set to

of

the Offset value

MODE

is

more negative than the value on the

display indicates that the

of

the

DMM

l0V

LEDs

is

offset

~

4-14

~

l I

u.

l

u

-

_,--

:-._------·---·,-

-_-,:;-·~----_

---

. -

D ·00000 ·

-0·00010

D ·00000 '

0·00000 '

o.ooooov

,--.'.-----..

0 0 0 B

~

.···

· · 0 u

,•a__J

+ D ·000

;---

1€JEIEIEle'e'EIEJ

>---

~!i§~

'---

----------._

-----<

___,/

D

·OOCWO

IQQgQQQ

'----

__J

DMM

!O

·

DMM

'

IQQQQQ

\__

R.

__j

Now the

DMM

gain error only 1?ay be measured:

-0·00010 '

-0.00010 V

Cancels DMM offset .

DMM Offset still cancelled

+9.99990V

=

10.00000

A A

OUTPUT OUTPUT

value = display setting

+ I

,-,

I

/_/ • I_/

I_/

+ (-0.00010V )

V

DMM

,-,

V

/_I

I_/

A

MODE display

Offset value

4-15

Full Scale Limiting.

combination result in

e.g

if

offset, the

-20.0000SV 4705 display as a signal output

The

OUTPUT display

greater cannot for the Range in use.

i.e. lOOµV

Deselection of Offset

display, the

4705 deselected tumed

Combining Offset and Error modes

(DC

Functions ·only)

By

combining Offset

to

carry instrument's linearity ( e.g. for a converter) without the and

gain errors.

This

is done

the

4705

then using Error Mode DMM's present.

In

this condition, readings from the represent non-linearities which would still

if

the D

errors.

This

facility also permits a

response

formy=mx+c.

in which y = instrument reading

of

set

an

off-scale output.

-19.99995V user

is requesting

and

causes Error 5

its previous ( valid) value.

than

Full

be

set

to

a value

and

Other

Ranges:

tums

the

offset

by

repressing the Offset key,

off

by

changing

out

a rapid analysis

by

output

gain

error

MM

were corrected for offset

of

the instrument to its input values in the

x = input value m = gain ratio c = zero offset value

The

4705

value

and

zero

is

set

together with

the

combination is invalid.

to

appear

to

the user,

cannot

Scale.

using Offset Mode

The

Offset

greater

lmV

Ranges:

<2%

of

Mode

red

Offset

to

zero.

and

for the

with the offset compensation still

any

4705

LED

Normally

FUNCTION

Error

need

to

DMM's

to

residual deviations in

OUTPUT display settings

user

will reject

offset which would

an

offscale

on

and

continues

be

set

MODE

than

the Offset

<200µV

Full

Range

clears the

O

FF

the

or

modes it is possible

of

a measuring

DMM

correct

compensate

its zero offset

to

zero offset,

to

quantify the linear

any

-100µ,V

output

The

the

MODE

to

a value

display

span

value

MODE

and

reduces

mode

hut

it

is also

RANGE.

or

A-D

compensate

and

for the

DMM

be

present

and

gain

of

to

is

e.g. for a

if y =

then the

Combination

1. U se Offset-mode

2.

3.

either:

= 1 -

~

or:

=

[

4.

Deselect

NOTE:

Test Key

DMM

9.99995x -0.00008, DMM

+ 5 +80

These directly from the the following procedure.

error

val_ue

With Error gain

error

value

page 4 - 13. ·

Use

setting

under response,

of

the

transfe:i; function is:

Instrument

µ (in

---

1Q6

µ(in%)]

1-

---

For procedure Therefore the inhibit

i.e. Offset

on

its 1

needs a gain compensation

ppm

and a zero

V.

compensation

procedure

and

record the

at

operation

Offset

suitable values

LED

mode

to

compensate

and

record the 4705

(ppm

or

to

check

test.

If

the

then

its readings will agree with those

4705

OUTPUT

ppm)]

100

in reverse sequence.

x Input value - y = y =

xlnputvalue-y=y=mx+c

these equations

must

any

deselected and

the

secondary

OV

range:

offset

compensation

figures

4705

MODE

(See

Note

to

compensate

4705

6 -

(y)

still lit, press Error key.

%)

at

operation

of

the

linearity

instrument

display

reading

follow the above sequence.

4705

has

other

sequence.

mode

cannot

when

Offset key operates in its

function

can

display, <luring

below)

for input offset

MODE

on

page 4 - 13.

for

the

instrument' s

MODE

8 -

OUTPUT

of

the instrument

has

perfect linear

and

to

be valid, the

been

be selected

the

Error

of

'%'.

be

display

displ_ay

(µ)

display

its linear

mx

designed to

LED

read

Use

· + c

is lit,

of

on

or

r·

l

.-,

[

n!

l,

[,]

[]

[1

(

[

' [

[

4-16

Tests available

There

any

are two stages

Safety

'Test'

and

Memory

sequence.

of

'Test'

checks,

mode.

cannot

The

first stage,

be

omitted from

. ~li -

JI

--------=:============

. ·-...

-----:-:-

.....

,.-··=·-=···=··--=--=·-=-=-·=···-=--=··=·····=··=--·-=.c.c·-=····~·-=-·=-·cc=-=cc··-~---cc=·-=c.=·~--··~

...

;;::.~-·-~-~-·-~-~

...

-~-~--~---~·._c.:.c:

...

~.-

~-

~-=··-~-----;;;

..

~

Il!

lll

111

Il

Safety and

On

first pressing the Test key, the 4705 carries out

Memory

Checks

three checks:

1.

Operation

of

the Safety trip, buzzer and reset

circuitry.

2. Calibration Memory integrity.

3. Over-voltage check. (High voltage when not in HV

state).

Mess,ages appear on the completion is signalled by the

MODE

Test

LED

display, and

going OFF.

The second stage Display and Key checks may be omitted by pressing any key

Display and Key Checks

If

the Test

Key

is re-pressed before pressing any

o~her

than Test.

other key, a visual sequence tests the front panel:

1.

Gas

discharge displays. .

2. Key

3.

LEDs.

Key contacts (user-selected).

4. Reset Check

The program ensures that user tests the Reset

action.

Press

Reset Key:

SAFEtY message is replaced by the running

The message and the buzzer stops sounding. Relay operation can be heard

<luring

the automatic checks

which follow.

5. Calibration

This

isa

Memory

sum-~heck

Check

ofthe

Non-volatile RAM.

Ifthe

check fails, the Message F AIL 6 appears, otherwise

no message.

6. Over-Voltage Checks

The 4 705 automatically tests

,the

over-voltage

detector threshold levels in Low Voltage state. If

the check fails, the message Fait 2 appears,

otherwise

PASS message indicates both tests

completed successfully.

7. The Test

LED

goes OFF.

The 4 705 remains in the key-contact mode until the Zero Key is pressed

deselected.

It

may then

or

test

is

be used normally.

N.B.

1.

At

ariy time

Test

sequence may be aborted by pressing

<luring

the second stage, the

Test Key again.

2. During self-test the instrument reset is

facility

Test Sequence

The

Front

or

<luring

Safety and

1. Initial Conditions

Test

sequence.

Memory

Ensure that OUTPUT

Spec

LEDs

not available.

Rear

panel terminals are' not energized

Checks

OFF

LED

is lit, Error and

are unlit. Check that Test

LED

unlit.

2. Press Test

Test

LED

Key:

lights as the checks begin.

is

The following table summarizes the

MODE

messages: ·

Message SAFEtY rumiing

PASS FAIL

6 only

Reason

First

stage

of

'test' operative.

N o failure disco

ve

red. Parity error in Calibration Memory check.

FAIL

2 only

High voltage can be present in Low Voltage state.

Any

combin~tion.

can appear m sequence, replacing the

of

these two F AIL messages

running

message.

8.

To

terminate Test before the

checks, press any key

other than Test:

Display

and Key

4705 returns to prior conditions.

display

3. Safety Trip Check

The 4 705 tests the safety trip circuits. message appears on the

MODE

The

SAFEtY

display and the buzzer will sound continuously when the trips have operated, and the

Reset

LED

flashes.

. 4-17

[

Display and Key Checks.

Visual Check Sequence Read this Note before pressing Test Key to start. NOTE:

1.

Press Test key - Test

then:

2.

MODE Display

(a) Initial presentation:

After pressing Test Key, the Visual Check sequence cominences. During this sequence observe that:

( a)

No

display segments or blocks are

missing

(b) Segments and blocks do not appear

spuriously.

( c) Inter-digit and inter-segment

'streaming' does not occur.

( d) All

sequence.

( e)

LEDs

or

incomplete.

LEDs

- All other

- Displays cleared momentarily,

are lit in their correct

are

not

lit spuriously.

LED

lights

LEDs

unlit

(b) Progressively, all seven-segment digits and

legends are displayed segment by segment.

( c) Final presentation: Nine commas are

displayed on

18 commas are displayed on

MODE displays.

OUTPUT and

(d)

MODE

4. ( a) Initial presentation:

Display

OUTPUT display then all

OUTPUT and

MODE

displays cleared.

+ I . 8

Polarity signs and overrange digit displayed.

(b) Progressively, seven-segment digits are

presented digit by digit.

( c) Final presentation.

[

r

..

,

[ [

lll

[

MODE

,,,

B

ppm

n

"'""

I I I I I I I I I

r

Nine segments and legends are presented.

(b) Progressively, all seven-segment digits and

legends are displayed segment by segment.

N.B. Commas are presented in the MODE display

sequence.

(c)

MODE display cleared.

3.

0 UTPUT Display

( a) Initial presentation:

OUTPUT

1

I I I I I I _ I I I

rem

,.

MODE

mVkO

...._.pA rnA

n•m

l

.il

First, then second blocks

displayed.

( d)

MODE display cleared.

5.

OUTPUT display digits are presented next, in the

same order as for the

6. LED Check sequence commences:

LED

(a) Test

lit in Left to Right sequence starting at key and ending at O FF.

(b) MODE display.

stays on, and other key

MODE

of

legends are

display.

LEDs

100 µ

0 '

0 8

MO/

ppn1

C

clG

C

[

are

_[

. ''l

Nine segements and legends are presented. 4-18

Symbol shown indicates that the keys are ready to be checked.

JI

I

-------------,----------~~~-~---'-'·-·---·-------·.

11

7. Key Checks

-------~----···--------·-------------·---

--

----'-~-

---

------

·---·--·------·--·---

------·

--

Il

11

~

N.B. The Zero key should not be pressed until it

(a)

+1

t Keys

Bach* immediately above

OUTPUT Display overrrange digit +

key should light the upper half

it.

k~y.

of

the digit

is

desired to terminate the Test Sequence.

Il

n-Test

Il

(

l l

Il

Each f key should light the lower half immediately above it.

OUTPUT Display overrrange digit

(b) FREQUENCY RANGE, MODE, OUTPUT RANGE, FUNCTION and OUTPUT keys should

cause their

(i) Reset key, which

and

(ii) Test key, which aborts the test.

In these tests the key-press operates a latch so that the display or

pressed. Only one key-press at a time

LEDs

to light, except:

is

of

the digit

y key.

inoperative,

is

recognized.

Et.-Test

IJ

ia-Test

LED

remains lit until another key

is

(c) · To Terminate the Test Sequence:

Press Zero key to check its operation.

- 4705 reverts to initial conditions.

- Test

(d) · Operate 4705 normally.

LED

goes

OFF

4-19

Warnings

High Pitph Audible Warning

and

Massages

(a) Sounds at approx 5 pulses per second

the High Voltage being connected to the terminals, when the OUTPUT TERMINAL VOLTAGE

DC

WILL EXCEED 110V

(b) Sounds at approx 1 second intervals with OUTPUT (c) Sounds for 1 second with blank FREQUENCY display when frequency auto-ranges up or down. (d) Sounds continuously when SAFEtY message

Low Pitch Audible Warning

(a) _ Sounds when any message

messages).

(b) Sounds when any invalid bus command

FREQUENCY/MODE

Error 1 Spec

:[+Lim,

Calibrate Mode

Error 3 Error 4

Error Error 6 Error 7

Error 8

Error 9 Error Error OL - Voltage Ranges

FAIL 1

FAIL2 FAIL3 FAIL4 FAIL5 FAIL6

5

EF

Calibrate Mode

Offset or

Error Mode

Calibrate Mode

(Resistance)

100V and 1000V Ranges

Selection error

Option not fitted

Externa! frequency -

- Current Ranges

- Excessive interna! temperature. F AIL 7 - 400V power supply fault - this 'trip' may

- Over-voltage reset itself if no hardware fault exists

-Control

- Precision divider fault. F AIL 8 - 3 8V power supply fault.

- Safety circuits tripped. FAIL 9 - 15V in-guard power supply fault.

- Calibration memory sumcheck non-parity.

display

Mode:[%]

-Lim]

data corrupted. and the Fail message

or 75V RMS.

is

<luring

displayed on the

Tolerance exceeds 100%.

The selected limit

OUTPUT OFF. Error 2

Incorrect FUNCTION, OUTPUT or FREQUENCY

RANGE for this calibration mode.

Correction out Temporary message. The selected deviation would exceed the full-scale value. Activation has been prevented. The resistance value selected exceeds the calibration value. Temporary message. The selected Voltage and Frequency exceeds the 4 705 interna! constraints. Activation has

been prevented.

Temporary message. The operation requested by the user is not

possible Temporary message. The requested range or function option is not

fitted. The externa! frequency is not present, machine will perform out of specification.

The output has been current-Iimited by an overload.

(If

in

switched OFF). The terminal voltage has been compliance-limited to 3V. (Load impedance too high)

the 3 second delay between selection

ON

in High Voltage State.

is

present on

MODE/FREQUENCY

is.

received.

is

of

limits.

.in

present machine configuration.

l00V

or 1000V range, OUTPUT

MODE

off-scale.

display

ofOUTPUT

<luring

displ~y (except recalled

is

automatically

self test.

is

temporary.

ON

and

SAFEtY - Test Mode running - Test Mode - Indicates test in progress. PASS

Recalled Messages ISS Addr

4-20

-Test

XX.XX

XX

Mode

- Firmware issue· number (selected by pressing Error then

-

IEEE

-Safety

-FAIL

and FAIL 2

488 Bus address

circuits tested by tripping: Press Reset key to continue test.

6 did not occur

<lid

not occur

as

set

on

<luring <luring

Address switch (selected by pressing Error then +Lim).

test of calibration memory parity, test of over-voltage thresholds.

-Lim).

[I]

]I

JI

]I

----·-~----·--···-·------------·---------------------·-·------------------------------------------11

Processor 'Busy' (Keyboard Unreceptive)

4705 will not respond to commands while legend 'B'

The except t0 override

KEY LEDs Basic Indications:

Lit - The labelled facility Unlit - The labelled facility Lit Green (Spec and Error

Lit Green (Store only)

<luring

safety delay.

only)-Other

printed ABOVE their keys, as directed by the arrows

-FREQUENCY

memory stores.

MODE

keys' facilities are reassigned to the secondary modes

RANGE keys are reassigned to select

is

present on the

is

selected and active.

is

not selected.

MODE

and OUTPUT displays

Fl-FS

JI

11

ll

li

ll ll ll

ll

·Warnings with Function OUTPUT RANGE 100V or 1000V

- A voltage in excess

ON

LED

flashing while in Low Voltage State with

-An

~

attempt to select output in excess of 1 I0V

Repressing OUTPUT ON key will switch the

DC

or AC Selected:

of

HOV

DC

LED

flashing

or 75V RMS has been selected (OUTPUT

OUTPUT

DC

or 75V RMS has been prevented.

HIGH

ON

VOLTAGE ON.

ON

or OFF).

l!

lf

li

lf

. 4-21

DANGIR

,..

'

THIS·

...

.

HIGH

INSTRUMENT

OF DELIVERING

A

llTHAl

VOLTAGE

IS -CAPABLE

lllCTRIC

SHOCK

!

m

L-:

__

-

__

-,

___

·,·,_,_

.•

=·11

r:

'

d_71

;·-

JlJ

~

,..

...

Unless

it is safe

DO

I+

I-

and terminals

It

your

you

NOT

Hi

Guard terminal is

sensitive voltage

can

instrument!

are sure

damage

to

do so,

TOUCH

or

Lo leads.

to

over -

that

the

4-22

DANGIR

l

] ]

l l

l

l l

S·ECTION 5

SYSTEMS THE IEEE

APPLICATION

488

INTERFACE ·

VIA

I ntroduction bus-connected devices under the direction or a

system controller.

Section 5 gives the information necessary to put the 4705 into operation on the

will

operators pitched at an introductory leve

information, refer to the standard specification,

which appears in the publication

Std. 488-1978.

Section Contents

The section

information together. These divisions are:

lnterface Capability - the permitted options

which have been implemented in the 4705.

Typical System - a briefview

using the 4705 to

Using the 4705

operation.

Programming I nstructions - how the 4 705

facilities have been transferred into remote commands.

Programming of Operational Functions - more

detail about the codes which control 4 705 operation.

Programming of

program the 4 705 to obtain specific types of readout.

be first-time users ofthe bus, the text

is

divided so as to group certain types of

checka

in

a System - implications ofbus

Bus

IEEE

DMM

Transmissions - how to

488 bus. As some

1.

For

more detailed

ANSI/IEEE

of

a typical process

calibration.

is

Programming Options

The instrument can be programmed via the Interface,

( 1) Change its operational state (Range, Function, (2) Transmit its own status data to other devices on ( 3) Request service from the system controller.

Capability Codes

To conform to the standard specification, it essential for a compatible device to encompass the full

The of the standard bus features, so that manufacturers can provide brief coded descriptions of their own interfaces' overall capability. A code string printed on the product itself.

The codes which apply to the 4 705 are given in Table 5.1, together with short descriptions. They also appear on the rear of the instrument next to the interface connector.

Appendix C fuller description of each code.

Code Interface Function

to: Frequency, Mode, Output, etc). the bus.

range of bus capabilities.

IEEE

488 document describes and codes each

ofthe

IEEE

488 document contains a

IEEE

is

often

not

Service Request - why the 4 705 needs the

controller' s attention and how it gets

Activation of Commands - what the 4 705 does

with the commands it receives.

Operational Sequence Guidelines a little

general · help with programming sequences.

INTERFACE

IE~E Standard

The 4 705 conforms to the Standard specification IEEE Interf ace for Programmable . Instrumentation'.

It can be connected to the

and set into programmed communication with other

4888-1978 -

CAPABILITY

488

'IEEE

IEEE

it.

Standard Digital

488 Interface Bus

SHl AHl T6

TE~

L4

LE~

SRl

RL2

pp~

DCl DT~

o/,

El

Table

Source Handshake Capability Acceptor Handshake Capability Talker (basic talker, serial poll, unaddressed to talk if addressed to listen)

No Address Extension Talker Mode Listener (basic listener, unaddressed to listen if addressed to talk)

No Address Extension Listener Mode Service Request Capability Remote/Local Lockout)

No Parallel Poll Capability Device Clear Capability

No Device Trigger Capability

No Controller Capability

Open-Collector Drivers

5.1

IEEE lnterface Capability.

Capability (without Local

5-1

Bus Addresses

When an

IEEE

488 system comprises several instruments, a unique 'Address' should be assigned to each to enable the controller to communicate with them individually.

One address

is

sufficient for a Datron instrument, as

the controller can add information to it to define

or

either 'talk'

'listen'.

I nterconnections

Instruments fitted with an normally communicate through a set interconnecting cables, specified in the

IEEE

488 interface

of

IEEE

488-

1978 Standard document. The 4705's interface connector, J27, is fitted on its

rear panel.

It

receives the specified connector, whose pin designations are also standardized and.shown in Fig. 5.1 and Table 5.2.

Fig.

5.1

J27 Pin Layout

12

24

13

J27

PinNo

1

2

3

4

·5 6 7 8 9

10 11 12

13 14 15

16 17 18 19 20

21 22 23 24

Name Description

Data

Input

DIOl DIO2 DIO3 DIO4 EOI DAV NRFD NDAC IFC SRQ ATN SHIELD

DIO5 DIO6 DIO7 DIO8 REN GND6 GND7

GND8 GND9 GNDlO

GNO

11

-GNO

Table 5.2

Data Data Data End Data Not

ready for Not Interface Clear Service Request Attention

Screening Safety

Data Data Data Data Remote Gnd Gnd

Gnd Gnd Gnd

Gnd 4 705 Logic

connected

IEEE

Output

Input

Output

Input

Output

Input

Output

or

Identify

Valid

Data

Accepted

on

cable ( connected

Ground)

Input

Output

Input

Output

Input

Output

Input

Output

Enab]e

wire

of

twisted pair with DAV

wire

of

twisted

wire

of

twisted pair with

wire.

of

twisted pair with

wire

of

twisted pair with

wire

of

twisted pair with

Ground

to

4 705 Safety Ground)

488-1978 -Connector

- Pin Designations

Line 1 Line 2 Line 3 Line 4

Line 5 Line 6

Line 7 Line 8

pair

with

(lnternally

to

NRFD NDAC IFC SRQ ATN

5-2

Controller Controls, Talks and Listens

<

~

D

Datron4705

Talks

and

Listens

-

Fig

5.2. Typical System

DIO1 DIO2

. DIO3

Data DIO4 lnput-Output

D

Hi

Lo

DMM

Talks arid Listens

lJ

Printer Listens

End

or ldentify

Inte

rface Clear

vice·Request

Ser Att

ention

Re

mote Enable

Dat

a Valid

Not

Ready for Data

Not

Data Accepted NDAC (Handshake)

010 5 DIO6 DIO7 DIO8

IFC

EOI }

SRQ

ATN

REN

DAV NRFD

5

. lnterface

Management Lines

} 3 Transfer

Control Lines

Il,

]]

]ij

]] ]]

])

Typical System

A typical system directect' by a controlling device able to:

(a) (b)

and ( c)

EXAMPLE

In

the system example (Fig. 5.2) the

programme task could be to check the

calibration against the

results.

events:

( 1) output commands must not be received printer and so the controller sends the general bus message messages, the controller makes all bus devices interpret any D1O-line flow commands,

The

controller needs to instruct the 4 705 to setJts

toa

'Unlisten'.

is

shown in Fig. 5 .2.

'Control' (lssue commands)

'Listen' (Receive data)

'Talk' (Transmit data)

OF

A SYSTEM IN OPERATION

4705,

following is a typical sequence

calibration point for the

When

data

as configuration

by

holding the ATN line true.

The

and print

DMM.

by

the

DMM

sending general

system is

DMM

out

the

of

These

or

the

or

data-

(6)As (Wired-OR function), the controller needs to discover which one sent the all devices one by one the ON.

(7)

sends the via the D1O lines to initiate the reading. After a short delay for measuremeni, the data transfer.

( 8) The controller identifies the D

poll. Finding that the reading is available, it sends

the

address, to activate both devices.

· (9)

releasing both devices to start the transfer. DMM to the printer. This to the printer, and byte is transferred Transfer-Control lines.

the

SRQ

facility

4700

is the

SRQ

It

next addresses the

GET message

and

SRQ'

s the controller when it is ready for

DMM's

The

sends its data, byte

talk address, and printer's listen

controller sets the A TN line false, thus

is

available to all bus devices

'SRQ'.

('serial poll'), finds out that

source and that its

DMM

(Group

DMM

by

data

must be in a form acceptable

to

ensure orderly transfer, each

by

'Handshake', using the three

It

therefore asks

OUTPUT

as a listener, and

Execute Trigger)

prepares output

MM

byte, via the D1O lines

by

a serial

The

is

The

(2)

address to force it to receive, followed 4 705 configuration commands ( including the

Output Disable message, to prevent the

receiving an inappropriate analog input). The instructions are passed along the output) lines as coded messages (bytes). used is lnterchange ).

(3) Although the 4705 accepts the instructions as they are passed, their implementation takes a short time. The controller would perform other tasks <luring configuring commands to the D

and the

( 4) operation, so the controller performs other tasks while waiting, such as configuring the printer.

(5)

addresses the 4705 as listener, and re-configures its Analog Output the 4 705 has executed its previous instructions, it

sets·

OUTPUT executed. message back to the controller via the Request) management line, if programmed to do so.

controller then sends the

ASCII (American Std. Code for Information

this period.

DMM

The

D

MM

The

controller next generates 'Unlisten',

OUTPUT

In

is

In

the example, it would pass

MM,

listen address have been sent.

also needs time to settle into stab le

On

by

an Output Enable message.

ON

immediately, otherwise the

set

ON

as soon as they have been

either case,the instrument sends a

4705's

D10

after

SRQ

(

data

The

'U

(Service

listen

by

DMM

input-

code

nlisten'

If

( 10) U sually the controller is also listening to this data

transfer to determine when it aid to the controller and printer, the another message with the last byte to be transferred (EOI-end management line ).

The

( 11) can start again

The

controller holds the

remote control.

GTL,

· permit temporary manual control

IFC

line is used clear any activity off the bus.

Sequences such as this are often assembled into programs points; changing functions, ranges and output levels as designed by the user. The program would also include 'display' messages to complete the printout in a recognizable form for, the user' s convenience. Programs must also cater for F

or identify, using another bus

sequence is complete, and the controller

at

another calibration point.

REN

It

can send an addressed command

or

some controllers can set

at

the discretion

to

check

DMMs

is

complete.

D

MM

line true when taking

REN

of

a device. The

ofthe

controller, to

at

many calibration

AIL

and

As

can send

false, to

ERROR

SRQs.

With a cause the within specification, using its 'calibrate' mode. ·

Datron

DMM

Autocal

DMM,

errors to be reduced until they are

other sequences can

an

·

.

5-3

Using the

4705

in a System

ADDRESSING THE 4705

Bus Address

The instrument address way miniature switch near the interface connector on the rear panel. Five any address

in

the range

code.

e.g. Switch setting -

5 4 3 2 1

is

set manually using a six-

of

the switches are used to set

00

to 30, using a binary

ADD

11010 = ADDRESS 26

'O'

'1'

'ADD'

The sixth switch variants. In the 4705, the position of the

switch

is

immaterial, as the normal bus addresses

is

provided for possible future

ADD

can be selected at either setting.

Addresses

With an address selected in the range O to

0-30

30

the

instrument may be controlled manually, or remotely

as part

of

a system on the Bus. The address selected

must be the same as that used in the controller

program to activate the 4705.

N.B. The selected address can be temporarily

displayed on the front panel when in manual control, by touching

Error and then

Guard.

AS

A4

A3

A2

Al

0 0 0 0 0 0 0 0 0 0 0 0

0 0 1 0 0 1 0 0 1 0 0 1 0 1 0 0 1 0 0 1 0 0 1 0 0 1 1 0 1 1 0 1 1

0 1 1 1 0 0 1 0 0

1 0 0

1 0 0 1 0 1 1 0 1 1 0 1 1 0 1 1 1 0 1 1 0 1 1 0 1 1 0 1 1 1

1 1 1 1 1 1

Table 5.3 Address Selection

0 0 0 1

1 0

1 1

0 0

0 1 1 0

1 1

0 0

· 0 1 1 0

1 1

0 0

0 1 1 0

1 1

0 0

0 1 1 0

1 1 .

0

O·

0 1

1 0 1 1

0 0

0 1

1 0 1 1

0 0

0 1

1 0

5-4

)-~-

Decimal

Code 00 01 02

t

03

04

05

06

07

08

09

10

11

12

13

14

15

16 17

18

19 20 21 22

23

24

25

26 ( e.g. above)

27

28

29

30

Remote Operation

When the 4 705 the controller, the legend

is

operating under the direction of

rem appears on the mode

display, and all front panel controls are disabled

except

Power and Reset.

On entering remote, any earlier (manual) selection

of

Error mode

operation, the facilities

is

cancelled. During remote

of

Error mode are excluded,

as they can easily be programmed into the controller.

Spec mode

can be obtained by bus command. There is no mode display on · the front panel

is

also cancelled, but 'Spec' information

<luring

remote

Spec

operation.

is

The 4 705 power-up sequence

performed as for

manual operation. After power-up, and on recovery

from a power failure, the 4705 generates an

SRQ

and prepares an 'RQS Status Byte' for

transmission to the controller as a response to its

subsequent

Calibration Enable

A 'Calibration Enable' command via the bus

serial poll.

is required to set the instrument into its Remote Calibration mode (the

CALIBRATION

ENABLE

keyswitch on the rear panel must already be set at

ENABLE). Selection

of

any address 0-30 inhibits

manual calibration from the front panel.

Address

31

(Illegal bus address)

This address configures manual operation only, inhibiting remote facilities. Address selected (with

CAL

key set to ENABLE), for

31

must be

manual calibration to be carried out.

Temporary Transfer to Local Operation (GTL)

The 4705 can be programmed to switch into 'Local' operation (Command GTL), permitting a user to take manual control from the front panel. The system controller regains

'Remote' control by sending the

11

lli

I!

~

)!

1

. e.g. programming

following overriding commands:

LAD

with

REN

True

The controller addresses the 4705 as a listener with

Remote Enable management line true (Low).

the This retums the 4705 from local to remote control. Any commands which had been sent period under local control will then be executed.

SDC

Specific 'Device Clear' commands are sent over the bus, retuming the 4705 to a predetermined state ( des.cribed later in this section).

<luring

the

Programming lnstructions

Programming Strings

From the example given earlier in this section it is , evident that the 4 705 requires an address code

of

followed by a series or commands to alter its configuration.

of

A series

'program string', each programming instruction

being position-independent. Each string will contain at least one programming

instruction ( detailed later in this section), but the 4 705 must receive the string can activate any instructions. The required terminator for the 4 705

'='

these commands can be sent together as a

instructions

~

device-dependent messages

'terminator' before it

is

the ASCII character

string

~

terminator

R4F301 =

Device-dependent commands

To

give

maximum scope for system programming, the bus operation of the 4705 differs in detail from manual operation, which is organized for ease front panel use. Some functions of the 4705 firmware are deleted for bus operation, as they are easily programmed into the system controller; and

extra functions have been made available to take

of

advantage

power. The following Alphabetic codes are used to establish

the required functioning

source:

Full Range/Zero: A Safety Delay Override: D Output Function DCV, ACV,

Output Range in all Functions:

Output Value: M

Frequency: H

Sense: S Guard: G

'Calibrate' trigger: C

Calibration Mode Enable: W

The following Alphabetic codes are used to select

and configure the messages to be passed by the 4705

via the

IEEE

User memory Output string terminators:

Notation

Specification tolerances

(relative: per unit):

Specification tolerances

( absolute limits Recall/Verify (relative): Service request origination:

Diagnostic information:

the controller' s added computing

of

the 4 705 as a calibration

ON/OFF:

DCI,

ACI,

R:

Bus:

of

output values:

):

of

0

F

R

I

K

L

p

u

V

Q

X

J

To assist in eliminating incorrect programming instructions, the 4705 checks for errors in the·string,

and generates a service request

if

error occurs or To ensure that the programming string does not set up a prohibited state, it also checks the whole string for validity. whole command string

For

Example: With the 4705 set in lOmV Range, a string received which contains an unacceptable

command to switch Sense connection ('S'

command). The user needs to set up a completely new, valid string; so the whole string discarded.

an option

If

it finds any errors in this phase, the

is

(SRQ)

is

called for but not fitted.

ignored.

if

a syntax

is

Table 5.4 lists the range

command codes available.

Fig.

5.

3 summarizes the way that front panel

functions are transferred to system operation.

of

device-dependent

5-5

CONTROL

Full Range/Zero

Calibration Mod~

Safety Delay

Function

Guard

Frequency Memory

(users Aide-Memoire) Output String

Terminators

Value Notation (Output to bus)

Main RegisterValue Output

Specification T olerance

Service Request

Output Range

Sense

Specification Tolerance (Absolute Limits Uncertainty)

RecallNerify

Calibration

Diagnostic (The calstore values r.elate set at the lime) Refer to Calibration and Servicing Handbook for description correct process.

Table

of

to the function

5.4

4705

of

CODE

AO

+ FullRange ) li.e.notifROset)

A1

- FullRange )

A2

"CAL" (Calibration Trigger)

co

"SET"

C1

"STO"

C2

"±O"(inDC)

C3

"Precal" (in AC) DC Coarse Gain

C4

DCLinearity

C5

Safety delay Active

00

Safety delay Over-Ridden

01

V (DC Voltage)

FO

F1

VA (DC Current)

F2

A-

F3

R (Resistance)

F4

LocalGuard

GO

Remote Guard

G1

Numeric value of frequency

H''''

Store next 16 ASCII characters

I

Crfollowed by Lf with EOI

KO

Crfollowed by Lf

K1

Crwith:EOI

K2

Cr

K3

LfwithEOI

K4

'Lf

K5

EOI with last character

K6

No terminator

K7

· Scientific with lengends

LO

Scientific with no legends

L1

Engineering with legends

L2

Engineering with no legends

L3

M±'"

Numericvalueof'Output' display

00

Output

01

OutputON

PO

24hours

P1

90days

P2 1 year

00

SRO on all specified states

01

SRO on Overload and Fail only

02

NoSROs Autorange

RO

100µ

R1

1m

R2

10m

R3

100m

R4

1

R5

10

R6

100

R7

1000

R8 R9

LocalSense

so

Remote Sense

S1

24hours

uo

90days

U1

1 year

U2

24hours

U3

,90days

U4

1 year

U5

'Output' Value

vo

'Frequency Setting'

V1

4705Status

V2

Software Status (Part No/lssue)

V3

F1

V4

F2 )

V5

F3 ) Recall 'Stored' frequency value

V6

F4

V?

F5 )

va

Calibration Mode Disable

wo

Calibration Mode Enable

W1

Zero Cal Store

xo

Gain Cal Store

X1

STO Cal Gain Factor

X2 X3

Zero offset ) Factory

X4

Gain offset ) corrections

Linearity (not AC) )

X5

Reference Divider Setting

X6

NotUsed

X?

User Message Recall

xa

IEEE

DESCRIPTION

Zero ) But not in Autorange

(AC Voltage) (AC Current)

OFF

10H

100H

1kH 10kH 100kH 1MH 10MH 100MH

)

488

Command Codes

888

Sectlon 8

)

) Output low limit to bus

)

) Output high limit to bus

)

I

, ,,,,

I .

I

,,,7n;

UUU,UL

i

((~)

OUTPUT RANGE

@aaäaaaä

100

1000

lkO

10k0

100k0

FS

~

Test

1gggg

0 l

AG

FUNCTION OUTPUT

Note: Frequency Range selection

is

not autoranges to correct range for

"H"

~

nt Panel Controls to System Operation

1MO 10MO 100MO

1g~gg

DC

Resel

_:

ON . .::....

required. Frequency

value.

= no comparable

OFF

commands

v

"'

Full Rarige

Zero ,

~

rdatron"

IN.STRUMFNIS

4705 AUTOCAL

MUL TIFUNCTION

"- CALIBRATOR

~

CONTROL

Full Range/Zero

Calibration Mode '

Safety Delay

Function

Guard

Frequency.

Memory (usersAide-Memoire)

Output String Terminators

Value Notation (Outputto bus)

Main

Register Value

Output

Specification Tolerance

Service Request

Output Range

Sense

Specification Tolerance (Absolute Limits of Uncertainty)

RecallNerify

Calibration

Diagnostic

(The calstore values r.elate

to the function

atthe

time)

set Refer

to

Table

Calibration

5.4

4705

ol

and Servicing Handbook for description correct process.

CODE

AO

+ Full Range ) li.e.

A1

- FullRange )

A2

"CAL "(Calibralion Trigger)

co

C1

"SET" "STD"

C2

"±0"(inDC)

C3

"Precal" (in AC)

C4

DC Coarse Gain

C5

DCLinearity Safety delay Active

D0 D1

Safety delay Over-Aidden

F0

V (DC Voltage)

F1

V-

F2

A (DC Current) A-

F3 F4

R (Resistance) LocalGuard

G0

Remote

Gt

H

....

Numeric value Store

I

Cr

KO

Cr

K1

Crwith:EOI

K2 K3

Cr LlwithEOI

K4

"LI

K5

EOI with last character

K6 K7

No terminator Scientificwith lengends

LO.

Scientific with

L1

Engineering with legends

L2

Engineering with

L3

M±*'*

Numeric value OutputOFF

00

OutputON

01

24hours

P0 P1

90days

P2

1 year

SRO

oo

SRO

01

02

NoSROs

RO

Autorange

R1

100/L 1m

A2

10m

A3

100m

A4

1

A5

10

A6

100

R7

1000

AB A9

so

LocalSense Remote Sense

St

24hours

uo

90days

Ut

1 year

U2

24hours

U3

,90days

U4

1year

U5

'Output' Value

vo

'Frequency Setting'

V1 V2

4705Status

V3

Soltware Status (Part Noilssue) F1

V4

F2 )

V5

F3 ) Recall 'Stored" frequency value

V6 V7

F4 ) F5 )

VB

Calibration Mode Disable

wo

Calibration

W1

Zero Cal Store

xo

Gain Cal Store

X1

STD Cal Gain F actor

X2

X3

Zero offset ) Factory

X4

Gain offset ) correclions Linearity (not AC) )

X5

X6

Reference Divider Setting

X7

NotUsed

X8

User Message Recall

IEEE

DESCRIPTION

Zero ) But

(ACVoltage) (AC Current)

Guard

of

ASCII characters

lollowed by followed

488

LI

by

LI

no

of

on all specified states on

Overload and Fail only

10n 100n

1kU 10kh 100kU 1MU 10MU 100MU

)

Mode Enable

Command Codes

not

in Autorange

not

if

RO

set)

see

Sectlon8

frequency

with EOI

legends no

legends

'Output' display

)

) Output low limit

)

) Output high limit to bus

)

to

bus

MOOE FREOUENCY

, n n k

I • LI

LI"'

I I

I

,

nn,-,nn/

I

'UUU,UL

~

I

Full

Rarge

Zero

~

rdarron

INSTHUMFNTS

4705 AUTOCAL

MUL TIFUNCTION

CALIBRATOR

~f-Jl

[±]1

t,

JI

DANGER

HIGH VOL TAGE

~&

!+

I·

Guard

@@@

u

•.............

::.:.;.·

.·

.:::.

:,

...

/::.·

·.::::·::-::

~

FREOUENCY RANGE

~

-

F1

F2 F3

i

((~~~)

OUTPUT RANGE

@Elelåi9:täeleJ

100

1000

lkO

10k0

100k0

!MO

F4

FS-.

10MO 100MO

1~ggg1gg~g

0 I

AG

DC

Rese!

_:

ON

-~

FUNCTION OUTPUT

OFF

r±11

·r·

•.

i

._.

Bus

operation

of

"Spec"

mode

__

)

'·

l.

·-,l-1·111

IT-,11'

Note:

Guard Sense Spec Error

-Remote-

sro

MODE

ser

Frequency is autoranges for

~

Range

not

required.

"H"

value.

- no comparable commands

Frequency

to

correct

selection

range

th

rh

-.

r-Jj

Fig 5.3 Transfer of Front Panel Controls

to

System Operation

.111

'11

. I

: - I

·1r

-

--

;

..,.

5-6

DANGIR

HIGH VOLTAGE

FRONT

terminals Full

THIS

,..

READ THIS: For manual operation, the47O5High Voltage lnterlocks employ at the OUTPUT

In received

text).

In manual

control

protection danger WHENEVER THE 4705 IS BEING USED EXCESS OF 75V, THERE MUST BE NO ACCESS REAR PANEL OUTPUT TERMINALS .

deliberate

system

of

is

actions

terminals.

applications,

from

the

system

operation

the47O5output,

to

exposed

intensified

the

users

by

before voltages in excess

the same

controller.

user

but

the

who

it

when

high

interlocks

(But see Safety Delay Override command

is exposed

is

not

the

speed

Output

CAN

require the same deliberate commands

possible

instrument

of

remote programming,

IN

A SYSTEM

or

REAR

carry

Voltage.

KILL !

of

11

0V

to

danger from high voltages also has

to

give

the same degree

is

under remote program control. This

TO

THE 4705 FRONT PANEL

the

ensurethat

DC

or

75V

RMS

of

built-in

so

it is ESSENTIAL that

GENERATE VOLTAGES

users

are generated

D1

in the

direct

OR

to

be

IN

...

,..

, Unless

DO NOT TOUCH

I+

.I

you

it

is safe

I-

and

Hi

terminals

are

or

Sllre

to

do so,

Lo

that

the

leads

DANGIR

5-7

Programming of Operational Functions

OUTPUT

The analog

O.B

( output disable ), and switched on to the selected

value by output are derived from the data used to set the

'Auxiliary'

registers.

Safety Delay

The High Voltage Safety delay ( 3 seconds) is

normally active command D potentially dangerous situations. åny Furiction or Range change ( including Autorange changes).

WARNING:

DONOTUSEDl

'FOR HIGH .SPEED OPERATION. TAKE

SAFETY PRECAUTIONS

PERSONNEL IN THE VICINITY.

Function

FB

Current), F3 configure the instrument to the required function.

Output Range

Rl

through to R9 configure the 4 705 to specific c

ranges as shown earlier in Table 5 .4. instrument in auto- range function, allowing the output value to be specified as a number without setting the actual range. Ranging down occurs 20% range. Ranging up occurs at Full Scale.

autorange, commands

Output Display Value

In

remote programming, the

of

setting the output value

M±***

either in numeric, scientific or engineering notation

(DC

of

ON/OFF

OUTPUT

O

1.

The amplitude and frequency

(MODE/FREQUENCY

(DB).

1,

hut the use

Voltage),

(AC

range,

is

i.

used to set the output value explicitly,

is

switched off by command

'M'

code and

'Main'

e.

(OUTPUT

It

can be overridden by the

of

this command sets up

UNLESSITISESSENTIAL

Fl

(AC

Voltage), F2

Current) and

Full Scale value

AB,

Al

and A2 are invalid.

(Main

Register)

incremental,

is

not used. Instead, Code

display), and

DJJ

is enforced by

TO

PROTECT

F4

(Resistance)

RO

of

next lower

'H'

display)

puts the

1,

method

of

code

(DC

the

at

In

(see examples below). the value is truncated to the correct resolution and the controller

'byte (see

section).

H igh

Voltage

The change from Low to High voltage state controlled by the same interlocks which govem the manual changeover (Refer to Section 4, page 4-7). To

effect the changeover, the command string:

'M

should be used if change is not involved. programmed to set the output into high voltage state ( for instance in separate

is

informed by

RQS

Outputs

(followed

OUTPUT

RB)

string~·

If the M code alone

OUTPUT

set in the Main Register ( 0

output voltage · will not ramp to high voltage state until the enabling string

If

the attempt had been made with

disabled

case.

It

should also be remembered that the output circuitry needs time to settle to its final value, especially should be included in the controller program to allow for this.

During these processes, the front panel wamings flashing manual operation.

panel should be restricted because the high speed of

programming in the IEEE interface

safety hazard.

already enabled

(OB),

the

if a range-change is incurred. Delays

LEDs

and pulsing tones operate as for

If

the resolution is too high,

SRQ

and

RQS

Status

status byte formats later in this

by_

voltage)

the

'0

is

attempted

'01

01

would be required in any

N evertheless, access to the front

O_l

='

is already on

If

a range change is

l'

should be senf as a

anda

(M****

(01),

the new value

UTPUT

display); hut the

='

is received. ·

adds_

range

...

=)

with

OUTPUT

of

to the

is

Examples

Required

Output Value

-153V +1.621257V

1.62125V

0.00256A

5-8

of

valid M codes:

Function Range M Code

F0

RMS RMS

RMS

Fl Fl F3

R7 R5 R5

R0

M-153 M+l.621257

M162125E-6 Ml

621.25 E-03

. M.00256

Output Display

-153.000V

+ 1.621,257V

1.621,25V"'

1.621,25V

2.5630mA

-(Autorange "'(Autorange to

to

R5

= lV)

R3

= lOmA)

Output Resolution

The

output resolution conforms to the · following

number

of

digits:

{

100µ,

Range 10

Range Code

Functions: DC

Voltage

AC

Voltage

DC

Current

AC

Current

Resistance and Local Sense

Resistance and Remote Sense

Frequency Display Value (Auxiliary Register)

In

remote programming, the incremental ( • method each auxiliary register value is input explicitly Code notation.

The set via the bus, although their contents using

Frequency Resolution

Frequency is resolved to three significant digits

(1

occupies four digit spaces, to accommodate the decimal point. digits, the value informed by formats later in this section).

Frequency and Voltage Constraints

On refuse any command for an output which exceeds the limits defined on page 3-6. The controller is informed by 'Error 7' SRQ status byte (see SRQ status byte formats later in this section).

Guard and Sense

These are configured into Local or Remote codes respectively:

of

setting the frequency is

H****

manual frequency 'Store' memories cannot be

'V'

codes.

% to lOOppm accuracy).

lOOV

and 1000V output ranges, the 4705 will

G8 - Local

. G 1

-.

SB

- Local Sense (forced when

F~ Fl F2 F3

F4!

S0

F4

!

S1

in numeric, scientific

If the significance is greater than three

is

truncated and the controller is

SRQ

Status byte ( see

Guard

Remote

Guard

Rl

3½

5½ 5½ 5½

3½

6½

On

lm

100

R2

4½

3½

5½

4½

6½

not

used. Instead,

or

engineering

can

the display this

SRQ

status byte

by

F2

or

10m

R3

1,)

by

be read

G or S

F3

has

lk

5½

4½ 5½ 5½

5½

6½

100m

10k

R4

6½ 5½ 5½ 5½

6½

S 1

These bus commands are subject to the constraints ofthe

4705 firmware.

ignore invalid commands, such as Remote Sense

when in

Calibration Enable and Calibrate

codes)

These are available for automatic calibration

4 705, under remote control via the

to the Calibration and Servicing Handbook.

- Calibration disable

W.0

Wl

- Calibration enable

- Calibration Trigger - '

C.0

-

Cl C2

-

C3

-

1

100k

R5

6½ 5½ 5½ 5½

6½

6½ 6½

been commanded and when FO, R3 and R4 been commanded). Programs for 2-wire

resistance in

~

Remote Sense ( available only when

or F 1 have been selected together with R5, R6, R7 and R8 selected in all ranges

4-wire resistance in

1

OOm

V range.

(only

if CALIBRATION

keyswitch set to ENABLE). equivalent to

As

SET key.

As

STD

As

±0

10 100 1000 lm R6 R7 R8

6½ 6½ 5½ 5½

6½

or

F4.

The

CAL

key .

key (in

DC)

10m 100m

6½ 6½

6½

Fl,

R2, R3 and R4 have

or

when

).

F4.

instrument will reject and

IEEE

key.

6½ 5½

6½

Rl,

F4

has been

Programs for

(W

and

of

bus. Refer

ENABLE

Refer to

1

Section 8.

'

R2,

FO

C

the

5-9

Programming of Bus Transmissions

!

Output String Formation

The 4705 can be commanded to output 'interna!' information to the system via the sending one

of

the specified 'recall' messages.

IEEE

Only one recall command should be included

488 bus, by

in

terminated string.

a

The length and construction depend upon the type

transmitted, and thus upon the codes used to program the 4705. The purpose ofthis explanation to describe the effects string format.

of

the string both

of

information to be

of

these codes on the output

is

As well as the information it contains, the string needs to be formatted correctly for acceptance by the

system. Many variations

these can be programmed for the type

of

format are available;

of

system in

use.

Figure

(This

·

ASCII

space

ASC

1

byte

11

'Space'

5.4

Breakdown of a Typical Output String

is

a general example - two specific 4 705 examples appear on page 5-12)

l

byte

Polarity

sign

Variable length

I

Num'eric in

standa~d

form

Exponent

delimiter

A format character to denote the

of

beginning present for recall command

Polarity sign ·

Replaced by an Functions.

an output string - not

X8.

For

ASCII

DC

space in

AC

functions, the

appropriate polarity sign is presented.

Numeric sub-string

Length depends on the resolution

of

the

information to be transmitted, and form depends on the notation programmed by

'L' code.

Exponent delimiter

'E'

Signifies that the numeric has finished

and the next three bytes form the exponent.

1

byte

Figure 5.4 illustrates the construction string, such as the 4705 output value.

of

a typical

Notice

that numerical data is reduced to a standard form, and scaled

by

means

of

an exponent in base 10. All

device-dependent messages use the ASCII code.

0

to

1

byte

Exponent value

The first

or

2

bytes

Exponent

value

of

'-'.

Because the value is never

0 or 2 bytes

I

Legends

(optional)

Terminators

the three bytes is always '+'

2

bytes

(optional)

greater than 9, the second byte is

always 0, and the third

is

a single /

decimal digit. / ,

Legends / ·

Inclusion is opt~onal, but if they are programmed in, two bytes are always present. The characters are appropriate

to the programmed state

Terminators

of

the 4705.

Two terminating characters are

available, as programmed by 'K' code. The

EO

I bus management line can optionally be programmed for simultaneous transmission with the last byte

of

the string.

Format Codes

The following pages list and describe the programming codes which determine the formation string. The codes on page 5-11 select specific types

5

..

10

of

ASCII

strings for retrieval.

of

the output

Recall/Verify (code V).

By

sending a V code the controller interrogates the

4705 to obtain information about its present status. Unless otherwise stated, the output strings are formatted as programmed by codes are as follows: \

VB

-

The

present Output value.

Vl

'.,__

The present Frequency setting

V2

- The present functional status.

The

response to

(space

The functions are represented by the same numerics as for programming. Output Range is identified

4705

V3·

The software status is the number as follows, in response to command code

R*F*O*G*S*W*Q*D*L*K*

is

programmed in autorange.

- Software status.

of

V2

is a standard

the internat program. This is formatted

K and L codes.

ASCII

In

addition, the

by

a lower case 'r' if the

part

number and issue

The

V

string:

terminator).

V3:

(space 890077 - numeric terminator)

A

Part No. Issue No.

(This status report is also available manually

by pressing

issue-number is presented on the display).

V4

to

VS

Codes held in volatile memory locations can only be set or selected manually. (Refer to page 3-7.)

The range listed

under'

Codes)'.

1-code (Aide-Memoire)

This allows the user to identify a specific calibrator with a designator up to 16 characters in length, stored in non-volatile memory. be placed in the to

ENABLE Sending the I command will store the subsequent 16 character string in memory. This string can be recalled using the

N.B. The 1-command and the

not be sent in the same string.

Specification Tolerance (Per unit - P codes).

The

P commands give access to Spec mode over the .

Error key then

- 'Stored' Frequencies.

V4

to

VS

recall each

of

legends transmitted by the 4 705 is

String F ormattirtg Commands

CAL

mode by tuming the

and sending the

X8

command.

Lim-.

The firmware

MODE

of

the five frequencies

Fl

to F5.

(K

The

4705 must first

CAL

Wl

command.

Wl

command must

!hese

and L

key

bus, also setting the calibration interval:

PB

- 24 hour;

On

being commanded by P code, the

calculates the Output U ncertainty

( as a

Diagnostic Information

The X commands recall the contents

volatile calibration memory locations. recalled are calibration constants stored at the most recent Autocalibration. They are used in the computations which establish the 4 705 output level, as corrections for long-term drift in the analog circuitry.

XB

Xl

X2

X3 Zero offset !

X4

X5

X6

X7

XS Recall message which was memorized

Activating the Recall Transmission

The 4 705 assembles the .appropriate output string in its output registers in response to the command. bus by addressing the 4705 as a talker.

String Formatting Commands ( K and L Codes).

The output string can be formatted and terminated to adapt to user's requirements. Scientific Engineering notation can be programmed, with

'per generates an output string formatted by K and codes. Legends are transmitted as

Absolute Limits of Tolerance

In

this case, the O commands cause the 4 705 to

calculate the high output value against the nominated calibration interval.

U.0'

- Low limit

01

- Low limit

02

- Low limit 1 year

03

- High limit

04

- High limit 90 day

05

- High limit 1 year

On

being commanded, the calculated value is output by the 4 705 in an output string formatted codes.

Zero Cal. Store Gain

calibration in 'STD'

Gain Linearity(not Reference Divider setting Not

earlier by the operator using

Pl

-

90

day;

unit' fraction

or

24 90

Cal. Store in

calibration

error factory

used in 4705

It

can subsequently be released onto the

low limit

hour

day

24

hour

AC

AC)

of

P2

- 1 year.

of

its current state

the output value) and

pu

(per unit).

of

uncertainty

by

K and L

of

certain non-

The

valqes

DC,

LF

. gain +

· \

gai.

n facto

\

C?de

I.

V,

P,

0 or X

4705

L

of

its

HF

or or

5-11

without descriptive legends. Two examples are given below.

LO

to

L3

Codes

configure the output string

notation:

I.B Scie·ntific notation with legends

Ll Scientific notation, no legends

·

L2 L3

Two sorts

a.

b.

Engineering notation with legends Engineering notation, no legends

of

terminator are available:

One or two bytes can be added to the end

of

string. These contain either Carriage Retum

· (Cr) or Line

followed by The

EO

Feed

(Lf); or both in the order:

Lf.

I bus management line can be programmed to set true simultaneously with the last byte both

1.

Scientific

Bytes-

of

the string.

Cr

and

Lf

are suppressed.

Notation

(Codes

1 2 3 4

L,

EO

I can be used even if

and L 1

).

6

7

the

Cr

8

The 4705 can also be programmed to transmit strings without terminators.

To

accommodate these variations, the system programmer · uses the codes:

KB

suppression (Cr,

Lf

and

EOI

No present as terminators)

Kl

Suppress

EOI

(Terminator

Cr

followed by

Lf)

K2

K3 K4

KS

K6

Suppress Suppress Suppress

Suppress

Lf

(Terminator

Lf

and

EOI

Cr

(Terminator Lf with EOI)

Cr

and

EOI

Cr

and Lf(Terminator

Cr

with EOI)

(Terminator

(Terminator Lf)

Cr)

EOI

last character)

Lf

and

9

K7

(No

10

11

Suppress Cr,

terminators).

12 13

14

EOI

15

16

17

18

K

all

with

Sp

Sp+

Two

ASCII spaces or one space and polarity

Outpllt

Value

Output Value Exponent: Legend(s): Terminator(s):

2.

Engineering Notation (Codes

Bytes -

Sp

Sp+

Two ASCII spaces or one space and polarity

Output

Value

Output Value Exponent: Legends(s):

Termi.nator(s): (Gode K6 programmed.)

- 0/1

Num~ric:

· (In

2

- 0/1

Numeric:

(In this case L3 was programmed. i.e. no legends)

this

(Code

case

L2

3

0.000000

E±(0

code

K1

and

0.000000

E±(W

0-9 0-9

to

1.99999 9

to 9)

L~

was

programmed)

L3).

4

0-9

I

to

199.9999

10·

10')

programmed.)

6

0-9

I I

0-9 0-9

7

0-9 0-9 0-9

0-9

8 . 9

0-9

10

0-9

+I-

12

13

0

14

0

/3 /6

EOI

VAR

- EOI with

line

last

E

11

E

+!-

0-9

SpN

byte

set

true

Cr

Lf

-

I

Descriptive Legends.

The following Legends will be fitted into the string after the exponent, if programmed by codes L0 or L2:

Recall Function

V0, V0, V0, V0, V0,

U0-U5 U0-U5 U0-U5 U0-U5 U0-U5

FO Fl F2 F3 F4

5-12

Legend Meaning Recall Legend Meaning

V

y,v

A

A,..,

DC

Volts P0-P2

AC

Volts

DC

Amps

AC

Amps

Frequency

pu per unit Hz

frequency

R Resistance

J

]

] ] ]

I

] ]

]

Service

The 4705 can asynchronously request service from the controller by putting the

SRQ the 4705 power ON, as the power-up defaultmode is

Request

SRQ line true (low).

is

always generated by the action of switching

QS.

A user can program the 4 705 to generate SRQs ( or not) using command code Q:

QJJ

Code

Serial Poll and RQS Status Byte

If

programmed for will pause in its operation to attend to the service request. determine which device initiated the does not react to parallel poll, hut only to serial poll, <luring instrument responds to its serial poll address by releasing a prepared bus. The RQS Request Bit (bit is

set true (Low) only if the 4705 has generated the

SRQ. This valida tes the remainder

which describes the causal condition by the state

codes listed in Table 5.5.

RQS Status Byte Composition

bit b8: Indicates a syntax error when true. bit

bit

- SRQ on any of the

Q 1 - SRQ on overload and any F

Table 5.5

Q2 -No

It

which each device

b7:

b6

true: Each combination

b6

false: Bits b5-bl each represent separate

SRQs generated

SRQ

response, the bus controller

first conducts a serial or parallel poll to

'RQS Status Byte' on to the

The RQS request bit, when true, confirms that the 4 705 was the originator. The RQS status byte valid unless bit b7 is true.

represents a single state as listed in Table 5.5

functional states within the 4705, and

RQS

the as listed in Table 5. 5

byte represents several states

~tates

in Table 5

AIL

state

SRQ. The 4 705

is.

addressed in tum. The

B7

of its status byte)

of

the byte,

of

bits b5-bl

.5

in

SRQ

is

not

Example

RQS status byte 01000001 represents:

0 - Syntax error.

1 - This instrument originated the SRQ.

0 - The following bits each represent separate

0 - This bit 0 - N o High Voltage waming. 0 - Auxiliary register not

0 - Main register not at limit.

1 - Output

The RQS status byte should not be confused with other status messages ( e.g. 'calibrator' or 'software'

status, described earlier under 'Recall/Verify') which are called up by the system controller' s program.

D10 Line Transmissions

Providing 4 705 sets the status byte ( serial poll. On receiving the status byte, the controller can address any device required to receive the data as a listener, and address the 4705 talker. Then the message programmed listener( s).

Fail Massages

The 4705 needs to react quickly to intemallygenerateq take rapid protective action. A fault condition may generate a train occur too quickly for some controllers to detect.

Such a train may be terminated by a message, which is detected by the controller. Thus the receipt of F as a final default condition, and not as indicating the origin cleared, if the 4705 has recovered, by pressing the

Reset key on the instrument front panel. As F

is

related to safety, it cannot be reset by remote

control.

with

bit b6 false:

states.

is

not used in the 4705.

at

limit.

is

ON.

QJJ

or Q 1 has been selected; when the

hasa

message to transmit over the

SRQ

line true and prepares the 'Recall' RQS

xl

100000) ready for the subsequent

is

sent via

F AIL messages and is programmed to

of

such interna! messages, which

AIL

5 by a controller should be taken

of

the fault. The F

AIL

D10

5 message can be

D10

lines, it

lines to the

FAIL

AIL

as

a

5

Table 5.5 lists the possible byte is valid only

if bit 7 (request bit) is true I

RQS

status bytes which may be transmitted by the 4705.

Legend: 1 = True, 0 = Fal se, X = 1 either 1 1or 0

bits b8

1

X

b7 b6

1

X

1 X

b5

b4

X X X

X

b3

X X

b2

X X

bl

Syntax! error

X

RQS

X

Combination Status Messages

X

1

0 X

X

1 0 X X X

X 1 X

0 X X 1

1 0 X 1 X X

X

Individual Status Messages

X 1 X 1 X X X X 1 X X

1

1 1

1

1 1

1

0 0

0 0 0 0 0 0 0 0 0

0

0 0

.1

0 0 1 0 0 0 1 0 0

1

X

1

X

0 0

1

1 1

0

1

Output'

1

Main l}egister limit reached

X

Auxili~ry Register limit reached

X

High

X

i

Recall 'message available

0

1

Error Error 2 CAL

0

Error 3 CAL Error 4 CAL

0

1 Error 5 Error or Offset mode: Overscale output requested

0 Error 6

Error 7

1

frequency constraints

X 1 X X X 1 X X 1 X X X X X X X X X

1

1 1

1

1 1

1

1 1 1 1 1

1

1 1 1 1 1 1 1

1

1 1 1 1 1

1

0

1 1

1

0 0 0 0 0 0

0 0

0

0 0 F ail O F ault condition rectified

0

·o

1 1 1 F ail 3 Control data corrupted

0

1 0 1 0 0

1 0

0

1 1

0 0 0

1 1

1 0 1 1 0 1

1

1 1 1

Error 8 General selection error

1 Fail 1 Over-temperature

Fail 2 Over-voltage

0

Fail 4 Precision divider fault

1

Fail 5 Safety alarm Fail 6 Cal. store sum check non-parity

0

1 Fall 7 400V power supply fault ( automatically resets if temporary)

Fail 8 3V power supply fault

1 Fail 9 15V ln-guard power supply fault

Reset. Instrument reset to power-up state

1 1 1 0 0 Error

1

1 1 Power-on

1

Overload - Current or Voltage limit

0

!

I

Request-for-service bit

i

I

ON

"Y:

oltage W

I

:

arning_

1 Specification not displayable

mode: Output not

ON mode: Incorrect Range/Function mode: Insufficient store span

CAL

mode: Resistance selected exceeds val. value

AC

Functions: Output has been limited by internat

EF

Externa! frequency not present

The

information in the

Table

5.5

Notes: (

Status Byte Coding

1) Power-up condition:

D0 F0 G0

K0

L0

M0

00

Q0

R0

(lV)

Device clear condition as power-up but K = and

'='

(2) Program string terminator:

activates preceding string.

S0

W0

L=

continue unchanged

Activation of Commands

Use of Terminator

The 4 705 activates single or multiple commands, only on receipt the

ASCII character

of

the recognized terminator. This is

'='.

Commands or command strings may be received while the instrument is in Local control, but will not

is

be activated even if a terminator

present, until the instrument is set to Remote control. The two 'Clear' messages

(DCL

and

SDC)

will be activated even

when in Local control.

Multipla Commands

Activation sequence

The input buffer has a capacity of 128 characters. Commands in a multiple string may be entered in any order, provided correct character syntax is observed. They are extracted from the buffer in received sequence and stored by alpha character into

Any

command stores.

store are over-written and lost. When a string terminator

in the store are validated. V alidation ensures that the proposed instrument state ( consisting changes programmed and those current states not reprogrammed) is valid. string being ignored and a syntax error generated.

New commands are executed in this sequence: K Output terminator format

L Output notation

Q

SRQMode W Remote Calfbration Enable I U ser Message lnput

00

OUTPUT

OFF

G Guard

D Safety Delay override F Function R Range M Main Register Value ( Output) A Full Range/Zero S Sense H Auxiliary Register Value (Frequency)

01

OUTPUT

ON C Calibrate Mode P Specification tolerance

U Specification limits V Recall/Verify X Diagnostic information

existing commands in the

is

received, the commands

of

those

Any

error results in the

A programmer may elect to change the sequence by

_inserting

.

basic constraints For command (e.g. will set re-programmed

, Succession of Multiple Commands

If

the input buffer

accepted to await their

terminators between commands, but the

of

the 4 705 will still be imposed.

example, if the function

F3=)

Output O

FF

as a result, and it must then be

ON

by the user.

is

not full, new commands are

is

changed as a single

the main program firmware

tum

for processing, and are extracted string by string. The input system design makes it extremely unlikely that the buffer will overflow, unless the 4705 is in Local Control and the

is

command input

fill

buffer to

up, the 4 705 places a hold on the

excessive.

bus handshake sequence. The command used to release the hold, followed by

If

this does cause the

IFC

DCL

to clear

IEEE

can be ·

the 4705 input buffer; but as·a general principle, this situation should be avoided by suitable

'reprogramming.

lnput Errors ,

Some unwanted commands are ignored. Others

enter the input buffer, and are rejected later.

'Read' commands

Before addressing the 4705 as a talker, it that it has been programmed by a

P,

is

essential

U,

V or X

command. Otherwise it will have no data to transmit.

Universal commands

LLO (Local Lockout) - ignored, no capability. PPU

(Parallel Poll Unconfigured) - ignored, no capability for parallel poll.

SPE (Serial Poll Enable) - sets the 4705 to serial

poll state, which when addressed responds with the RQS status byte. This byte contains the condition ofthe request-service bit (bit 7).

If

the 4 705 is requesting service; bit 7 will be true, the other bits describing the service required.

SPD (Serial Poll

Disable)-

returns the instrument

to serial poll idle state.

Addressed commands

PPC (Parallel Poll Configure) - ignored, no

capability.

GET (Group Execute Trigger) - ignored, no

capability.

TCT (Take Control) - ignored, no capability. GTL

(

Go

To

Local)-

instrument returns to Manual

Control. The controller regains remote

control by addressing the 4 705 as a listener

REN

with

line true. \

5-14

11

I

Il

]]

I I

I

Clear Commands

When the 4 705 receives either of the two 'Clear'

messages, to a selected device) it will default to the predetermined state defined below. During the time taken to default, the held. These commands are effective even in 'Local' control.

A?

FP

R~

MjJ

H(value)

o,

S'1

00

Q"

D9

Wft

c'i

P?

U?

V?

X?

K*

L*

The frequency values held in 'Store' volatile memory locations F state described on page 3-

(DCL

Not Active ( see M code) DC Autorange 1 V default Where value

. Where value is

Local guard Local sense OUTPUT SRQ Safety delay active Calibration disabled Not Not Not Not Not Unchanged Unchanged

(DCL

is universal and

Volts

on all specified states

active _:·disabled by active active active active·

and

SDC)

SDC

IEEE

1-

interf ace handshake is

is

zero

lkHz

OFF

state

F 5 are reset to the default

7.

is

a:ddressed

W0

Operational. Sequence Guidelines

Most interf ace communication tasks require sequences of coded messages to be sent over the interf ace. Many · controllers assign a single programming instruction to a complete sequence, so

it

is

advisable to study the available controller

capabilities carefully before attemping to program a ·

system. Because the

certain latitude in bus protocol, considerable differences may be found between programming instructions and operating sequences from one make of controller to another. Consequently, the following sequences are recommendations only.

IEEE

Std 488 (1978) allows a

Data Transfer

UNL

LAD1 Each address sent enables a specific LAD

Inhibits all current listeners device to receive future data bytes.

More than one address · may be sent if

0

multiple listeners desired. ·

I

TAD

DAB1

The address sent enables a specific

4

705

device to send data. The

already programmed to prepare data. Data talkers to all currently-enabled listeners.

bytes sent by currently-enabled

must be

I

DAB

0

UNT

UNL LAD T

AD DAB UNT

Serial Poll UNL SPE

TAD

SBN

or

SBA

SPD

UNT

SPE SPD

SBN

[

SBA

Untalk

It

is

highly desirable that a sequence which causes a device to be addressed as a talker should be terminated by an 'untalk' command.

Disables the talker on receipt of the last character.

= unlisten = listen address = talk address

= data bytes

of

specific device

of

specific device

= untalk

Inhibits all current listeners Puts interface into serial poll mode <luring instead of data when addressed. Enables a specific device to send status.

0

Within this loop, device should be sequentially enabled.

which all devices send status

l Status byte sent by enabled device:

~

lf

SBN, loop should be repeated.

sent, the enabled device having sent

remove Disables serial poll mode. Disable last talker.

it.

SRQ

and will automatically

is

= Serial poll enable · l

= Serial poll disable = Status byte negative where bit 7 = 0

= Status byte affirmative where bit 7 = 1

If

SBA

identified

as

..

'

5-15

SECTION 6 SPECIFICATIONS

General

POWER SUPPL V

Voltage Line Frequency

~

Consumption

Fuses 2201240V

100!120V

100/120/220/240V±10% 48Hzto62Hz 370 VA normal

660 VA full power

3.15A

6.25A

MECHANICAL

Dimensions

Weight

SAFETY

PEAK

TERMINAL VOLTAGES

Guard to Ground 920V Loto Guard 920V Loto Ground 920V Hi

to

Guard 1556V

Hi

to

Ground 1556V

Rear Panel Digital lnputs-

Hi

to

Lo

to to Guard 920V toGround

Height 178mm (7") Width 455mm (17.9") Depth 564mm (22.2")

35kg (77Ib) The 4 705 has been designed

to meet BSI 4743, IEC 348 and UL 1244 specifications

1556V 920V

0Vto

+5V

N.B.

Digital Common is internally connected to Ground

ENVIRONMENTAL CONDITIONS

Operating temperature :

0°C

to +50°C

CAUTION.

Above 30°C on 1 kV Range: maximum output power is derated

-40°C

Storage Temperature Maximum Relative Humidity 75% at 40°C

Warm-up Time One hourto meet

to + 70°C

Non-Condensing

all

specifications

OPERATING INDICATIONS

lndication Symbols lit on displays and

Scale Lengths

Output Display 6 Frequency Display 3 Digits plus store location Mode Display

illuminated keys

1

/?

Digits maximum

1

/?

Digits maximum

6

6-1

DCVOLTAGE

Accuracy

Range

100.0µVto

100.0000mV

1.000000V

10.00000V

100.0000V

1000.000V

Stability

24 hour ±(ppm

OUTPUT+

ppmFS) 24 hour

(1) (2)

2+1µV 2+1

1+0.5 2+0.5 2+0.5

Noise (4)

Bandwidth 2.5kHz Average

1V

(RMS)

4µV 4µV

10µV

120µV

2.5mV

Range

100µV-100mV

10V

100V

1000V

Accuracy Relative to Calibration Standards Calibration

±(ppm

OUTPUT

23 C

±

1'C

6+1µV 6+1 6+1 6+1 6+1

Over

1 Line Period

(pk-to-pk)

0.2µV 2µV 5µV

50µV

600µV

+ppmFS)

90days

23''C±

1''C

15+1µV 15+1 15+1 15+1 15+1

Average

1 O Line Periods

(pk-to-pk)

0.5µV

25µV

200µV

(2)

1 year

23"C ± 10°C

35+5µV 35+5 35+5 35+5 35+5

Over

2µV

Uncertainty

(ppm)(3)

1Ö+1µV

7 5 9

12

DC-2Hz

(Typical Null

Detector)

(pk-to-pk)

0.1µV

0.5µV 2µV

25µV

150µV

Temperature

Coefficient

OUTPUTl°C)

8°C-

33°C

-,

2.0

1.5

1.0

1.5

2.0

(±ppm

13°C

38r'C

Output Output

Reslstance Compliance

1000 <0.1m!! <0.1m!! <1m!! <10mH

-

25mA 25mA 25mA 25mA

Notes:

(

1)

For same conditions between 18

(2)

FS=2xRange

(3)

Factory calibration uncertainty using automated calibration equipment. Datron can provide better traceability. Contact factory for details.

(4)

For 10kHz-wide band, multiply 2.5kHz figures by

·c

and 28' C

2.

For RMS, divide pk-to-pk figures by 6.

Other Specifications

Output

Overrange Voltage Sensing Guarding Common Mode Rejection

Settling Time

True bipolar output capable of delivering 100%

on

100µ

V to 1

OOV

ranges, 10% on 1 Selectable remote or local voltage sensing on 1 V to 1 Selectable remote 140dB at DC to 400Hz.

To 1 ppm of step size To 1 Oppm of step size To 1

OOppm

or

local guard connection. Max Guard to Ground voltage of 650V rms (2.5kV flash test).

<5s.

of step size < 1

<1

s.

OOms.

6-2

11

OOV

with respect to Output Lo.

OOOV

range

(11

OOOV

OOV).

ranges.

;o··

I .

l

,.

----··'

'

·-

-,

- .

DANGIR

HIGH VOLTAGE

.

Lt

THIS

..

INSTRUMENT

OF DELIVERING

A

llTHAl

IS CAPABLE

EllCTRIC

Guard terminal is

sensitiva voltage

SHOCK

to

over -

!

,.

Unless

,

-DO

I+

.

It

your

you

it

is safe

can

instrument!

.are

damage

sure

to

do so,

NOT TOUCH

I-

and

Hi

or

Lo leads

terminals

DANGIR

that

the

ACVOLTAGE

'~!(:

Accuracy

Range

1.000mV to

100.000mV

1.00000V

and

10.0000V

100.000V

1000.00V

Frequency Stabil ity

(Hz)

10-31 32-33k

30k-100k

10-31 32-33k

30k-100k

10-31 32-33k

30k-100k

45-330 300-10k 10k-33k

24hour

±(ppm

OUTPUT

+ppmFS)"

(1) (2)

170+10+10µV

80+10+10µV 80+10+10µV

150+

20

80+

10

80+

10

150+20

80+10

80+

10 .

150+20

80+20

150+30

Accuracy Relative to

24hour

23°c ± 1°c

250+60+10µV 200+60+10µV 800+80+10µV

250+60 200+50 250+80

250+60 200+50 250

+80

250+60 200+50 250+80

±

(ppm

Calibration

OUTPUT +

23°c ± 1°c

300+60+10µV 250+60+10µV 800+80+10µV

300+60 250+50 300+80

ppm

90days

Standards

FS)

(2)

23°c ± 10°c

400+60+10µV 300+60+10µV

0.1%+60+10µV

1

yea·r

400+60 300+50 500+80

400+60 380+50 500+80

400+60 300+50 500+80

-iiw

I

:---'-':-

~

Notes:

(1)

For same conditions between 18 C and 28

(2)

FS=2x

Range.

(3)

Factory calibration uncertainty using automated calibration equipment. Datron can provide better traceability. Contact factory for details.

(4)

Estimated. not fully traceable.

(5)

fredominantly

(6)

For Frequency Range or Output Range changes. Function changes. OFF ON changes. and Frequency changes between S_ettling

•

In

remote operation via the IEEE 488 lnterface. hardware switching occurs under the control of 'H' (Frequency) codes. Any transfer (up or

down) between the undermentioned frequencies must be regarded as a frequency range change. Settling Time should be allowed as for

·other

•

For

se~ling

second harmonic (negligible error on mean sensing instruments).

Times are doubled.

Specifications. · ·

300-301Hz

3-.00

33.0 -33.1 kHz

to 1 Oppm

of Step Size,

·31

-32Hz

-3.01 kHz

multiply

C.

all

times

by

31

1 .5.

and 32Hz: the

6-4

Calibration Temperature

Uncertainty (ppm)

(3)

Coefficient

(±ppm

33

OUTPUT

C-13··c

8

C-38

Total

Harmonic

''C)

C

Distortion

(%)(5)

Output I mpedance at Zero to Full Load

Regulation

Output

Compliance

110+12µV 250+10µV 560+11µV

160 130 170

160 130 200(6)

190 170

250

Other Specifications

Scale Length

Voltage Sensing

Guarding Common

. Settling Time (6)

Frequency Accuracy Maximum Load

Capacitance

Mode Rejection

10 10 10

6 6 6

6 6

10

10 10 10

9%

to 200% of Range, 1 mV to 1 00V ranges.

9'%

to 110% of range, 1 000V range

Selectable remote or local voltage sensing on 1 V to 1 000V ranges.

Selectable remote or local guard connection. Maximum Guard to Gound voltage 140dB at DC to 400Hz. To 1 00ppm of step size (double for range changes);

1 0 -

32Hz< 1 Os.

32-

330Hz<3s.

>330Hz<1s.

< 100ppm, typically < 10ppm. 1 V to 1

00V

1 000V range: 300pF.

ranges: 1 000pF.

0.1

0.04

0.1

0.04

0.1

0.04

0.2

0.1

30H

at all frequencies

Typically

0.001% FS to33kHz

increasing to

0.02% FS at 1 00kHz (2) Typically

0.002%FS to33kHz

increasing to.

0.02% FS at 1 00kHz (2)

Typically

0.002%FS

(11

to33kHz

00V).

(2)

. -

1 V Range: 10V Range: 60mA

<3.3kHz, >3.3kHz,

25mA

120mA

15mA 65mA

650V

RMS (2.5kV flash test).

6-5

VOL TAGE/FREQUENCY CONSTRAINTS

1000V

Output Voltage

(Log. Scale)

200V

100V

20V

10V

Frequency

Range Spans

100Hz Range

45Hz

1300

330

I

-----------'

I·

1kHz Range

3.3k I

_10kHz

Range

! 3k 33k I

I

3ok

33kHz

I

100kHz Range

100k I

100kHz

1100V

1000VRange

200V

90V

100V Range

20V

9V

6-6

1V

10V Range

(Lower

Ranges

also cover

thefull

frequency

span)

0.9V

10

30

-I

100

300

Output

I I

I

1 k 3k

Frequency

(Hz)

(Log. Scale)

10k

30k

100k

Voltage

Range Spans

CAPACITIVE LOADING CONSTRAINTS

.8

6

Volt-

Hertz 3

7

X

10

Volt-Hertz Power Lim it versus Capacitance Load

7

5

4

2

Full Specification

specification

100

200 300 400 600 800 1000

I•

i

ii

-

,

...

(1

kV

Range}

4-wire:

11111

11111 1 11111 1

Il

11111 1

typical

I

-

,2,-vy)re

-

I

Il

...

"'-

~

"'1111

..

~

I

Not

..

(>1000pF)

Vaiid

~i,..~i,..-

.....

_

...

Total Load Capacitance - lncluding Leads

(pF)

6-7

'oc

CURRENT

Accuracy

(

Range

OUTPUT+

100.000pA

1.00000mA

10.0000mA

100.000mA

1.00000A (4)

Noise

2.SkHz Average Over (RMS)

5nA 6nA SnA

50nA 30nA

.1µA

25µA

Stab11ity

24 hour ±(ppm

ppmFS)

(1)

15+10 15+10 15+10 15+10 15+15

Bandwidth

1 Line Period

(pk-to-pk)

500nA 400nA

30µA

Accuracy Relative to Calibration Standards Calibration

±(ppm

OUTPUT

(2)

6nA

24 hour

C±

23

20+15 20+15 20+15 20+15 20+20

Average Over

1

O Line Periods

1 C

(pk-to-pk)

2nA 2nA

20nA

20µA

+ppmFS)

90days

23 C ± 1 C

50+15 50+15 50+15 50+15

115+20

(2)

1 year

23

C±

115+20 115+20 115+20 115+20

250+30

10 C

Uncert_ainty

(±ppm)(3)

a,,;,f~_,,h,l.

35 33 33 33 80

T emperature

Coefficient (

OUTPUT'C)

a··c-13C

33'C-38C

30 12 12 12

30

±ppm

Output Output

Resistance Compliance

>2G!! >2GU >200MU >20MU >1MU

3V 3V 3V 3V 3V

.f'

Notes:

(1)

For same conditions between 18°C and 28°C.

(2)

FS=2xRange.

(3) Factory calibration uncertainty using automated calibration equipment.

Datron can provide better traceability. Contact factory for details.

(4)

Typical above 1A.

Other Specifications

Output Overrange Settling Time Local Sense Only. all ranges

Max.

reactive loads

True bipolar output capable 100% on all ranges.

sto

full specification.

1

1mH(<1µs).

100nF,

of

delivering

6-8

±2A.

I

~

\,

\

]

],

,.

THIS

...

HIGH

INSTRUMENT

OF DELIVERING

A

llTHAl

~•(

DANGIR

VOLTAGE

IS CAPABLE

ILICTRIC

FRONT

C terminals

Full

or

Output

SHOCK

REAR

carry

the

Voltage.

.Lh_; ....

_.

I

•

I •

THIS CAN KILL !

Guard terminal is

to

sensitive voltage

It

can

your

r

Unless

DO

I+

you

it

is safe

NOT

I-

Hi

_instrument!

are sure

TOUCH

or

damage

to

do so,

Lo leads

over -

that

the

I·

and terminals

DANGIR

6-9

ACCURRENT

Ac.curacy

Range Frequency

100.000µA

1.00000mA

10.0000mA

100.000mA

1.00000A(4)

(Hz)

10-1

1k-5k

10-1

1k-5k 10-1 1k-5k 10-1 1k-5k 10-1 1k-5k

---

Stabil ity

24hour

±(ppm

OUTPUT

+ppmFS)

(1) (2)

k

50+20 70+30 50+20 50+20 50+20 50+20 50+20 50+20 50+20 70+30

23°c + 1°c

400+80 400+80 550+100 200+80 350+80 200+80 350+80 200+80 350+80 350+80 400+80 550+100

Accuracy Relative to Calibration Standards

± (ppm OUTPUT + ppm

24hour 90days 1 year

(7)

23°C+

550+100 220+80 350+80 220+80 350+80 220+80

400+80

550+100

1°c

(7)

FS)

(2)

23°C+

500+100 650+160 350+100 450+100 350+100 450+100 350+100 450+100 500+100 650+160

10°c

(7)

[---

t]

-~

-,

n

r---~

]]

Notes:

(1)

For same conditions between 18°C and 28°C.

(2)

FS=2x

Range.

(3)

Factory calibration uncertainty using automated calibration equipment. Datron can provide better traceability. Contact factory for details.

(4)

Typical above 1

(5)

Predominantly second harmonic (negligible error on mean sensing instruments).

(6)

For Frequency Range or Output Range changes, Function changes, OFF ~ettling Times are doubled.

In

remote operation via the IEEE 488 lnterface, hardware switching occurs under the control of 'H' (Frequency) codes. Any transfer (up or

• down) between the undermentioned frequencies must be regarded as a frequency range change. Settling Time should be allowed as for 'Other Specifications. · ·

• For settling to 1

(7)

Assumes similar load time constant to that at calibration.

A.

.31-32Hz

300-301Hz

3.00 -

3.01

Oppm

of Step Size, multiply all times by 1.5.

kHz

33.0 -33.1 kHz 330-331kHz

1

0N

changes, and Frequency changes between

31

I

and 32Hz: the

6-10

I

J

Calibration Temperature

Uncertainty (ppm)

(3)

400 900 255 255 255 255 20 255 255 290 440 40

* Typical effective output capacitance = 200pF } Negligible on other Ranges. ** Typical effective output capacitance = 0.5µF

Coefficient

(±ppm

OUTPUT'°C

3°C-13°C

33°C-43°C

20 40 0.5 20

·20 0.2 20

20 20

40

Total Harmonic Output Distortion lmpedance

(%)(5)

0.2

0.2 30MH

0.2 3MH

0.2

0.2 300kH

0.2

0.2 30kU**

1.0

Typical

100MH*

Output

Compliance

3Vrms

Other Specifications

Scale Length Settling Time (6)

Frequency Accuracy < ± 1 00ppm, typically 1 Maximum Load Capacitance 1 Maximum Load lnductance 1 mH ( < 1 µs) Local Sense Only, all ranges.

9% to ~00% of range, all ranges.

OOppm

To 1

OnF ( <1

of step size ( double for range changes): 10-32Hz<10s 32-330Hz<3s >330Hz<1s

µs).

..

Oppm.

I:

6-11

RESISTANCE

Accuracy

10.ooooon

100.0000!l

1.000000k

10.00000k

190.0000k

1.000000M

10.00000M

100.0000M

* 2-wire Sense 24 Hrs and 90 days stability }

Range

(1)

(2-wire

or

4-wire

Stabil ity Accuracy Relative to Calibration Calibration Temperature

* 24 hour

±(ppm

OUTPUT

+ppmFS)

(1) (2)

l..._

10

2.5

2.5 3

2.5

2.5 8

30

sense)

Standards

OUTPUT

±(ppm

24hour

·

23°c ± 1°c

12

3 6

3 3 6

10 25 60

40 100 200

+ppmFS)

90days

23°c ± 1°c

30

6 6

(2)

1 year

l23°C

± 10°C

75 25 20 20 10 20 10 25 20

40 50 125 500 200

90 days accuracy

1 year accuracy

4-wire values 4-wire values

±0.1 ±o.2n

Notes:

(1)

Range figures are nominal, actual calibrated values are displayed.

(2)

FS=2xRange.

(3)

Factory calibration uncertainty using automated calibration equipment. Datron can provide better traceability. Contact factory for details.

Uncertainty Coefficient

(ppm)

(3)

Os~lterltei-

1

10

40

65

n

OUTPUT/°C)

(±ppm

8°C-13°C

33°C-38°C

6 2 2 2 2

6 10 20

Specified Maximum

Addition

Current Current . uncertainty

(Is) (lm)

forls~l<lm

(ppm)

(8.5x10 (~.5x10

(a.sx10

(15x10 (15x10

2

1

8

9

10mA 100mA (10x10 10mA

25mA

1mA 10mA

100µA

'100µA

10µA

1µA 1µA

2.5mA (8.5x10 1mA

100µA (10x10

10µA 10µA

al

12

)

3

12

)

4

)

12

5

)

12

6

)

12

)

12

2

)

1

)

12

Other Specifications

Connection

Guarding Protection All resistors fuse protected to max applied voltage of 120V RMS.

Selectable 2 or 4-wire connection to resistors. 2-wire displayed value includes interna! lead resistance.

or

Selectable remote

local guard connection.

6-12

I

i

]

I

J

l

l l l l

SECTION 7

SPECIFICATION

lntroduction

The factory calibration of the 4705 ensures trac.eable accuracy to national standards. Figures of performance are quoted in the specifications of

Section 6, related to time since calibration.

This section deals with user-verification ofthe 4705 perf ormance to specification.

as

two independent vertifications:

AC

and then

specification.

It should be carried out

DC

specification

DC Specification Verification

Verification upon receipt of a 4705 Autocal

Multifunction Calibrator

Each instrument leaving the factory

DC

its nominal values in

to actual values in Resistance. The Accuracy

specifications can be roade relative (i.e. Traceable)

to National Standards, by the addition

Calibration Uncertainty figures printed in the specifications. Thus either the 90-day or 1-year accuracy specification

with traceable Reference Standards.

The 24:-hour stability specifications can only be verified following a calibration operation or calibration check against the user' s Reference

Standards.

voltage,

is

verifiable by comparison

is

calibrated to

DC

Current, and

of

Datron's

, Equipment Requirements

VERIFICATION

DC

Current - A

N.B. To allow the same value to be set on

CAUTION When choosing a set

DC

Voltage source, calibrated to

at

suitable accuracy

lV

and lO0mV. ·

Example: The standard voltage

source used for

Voltage, with the. Datron

4903

- The battery-operated null detector DC

used for

- A set

- altematively, a D

of

suitable accuracy.

DC

the range, the . shunts may be of decade values. Then the same Null Detector sensitivity can be used on each range.

shunts ensure that their power dissipation· ratings are sufficient to avoid permanent degradation from the self-heating effects being checked. This applies particularly to the 1 Amp shunt.

accuracy may be the voltage across the set of calibrated current shunts. Example: Datron l081 using

Voltage.

calibrated current shunts of

Voltage source for each

"compute" mode.

approximately

DC

Switching Unit.

of

the current

MM

of

us'ed

to measure

DC

five

current

sufficient

DC

Voltage - A Standard

suitable accuracy

Example: Series bank of 10 standard

- A Precision Divider Example: Datron 4902 High

- A battery-operated null detector

I

with variable sensitivity, able to withstand 1200V across its input terminals Example: Keithley Instruments

DC

Voltage source of

cells and Datron 4904

Staridard Cell buffer.

Voltage

divider and Datron 4903

DC

Switching Unit

· Model 155

Resistance - a set of standard resistors covering

100

to

lOOMO.

should be 4-wire type.

- an acc:urate resistance bridge, or other ratiometric device for measuring resistance to the required . accuracy.

- a Datron 1081 used as a transfer measurement device.

The

100

to lOkO

7-1

.

..

;

."·.

~r

[ .

Notes

on

the Use of the

Null Detector

The null detector is connected in the

DC

between the

high-input-impedance device should be chosen to

reduce off-null currents due to differences in the

outputs of the

battery-operated instrument adequate isolation. Some null detectors possess high input impedance only when their readings are onscale, so care should be taken to ensure that drain currents from the excessive. This applies particularly if the isa

standard

important:

l.

The null detector should be connected to the 4705

{or 4705 load resistor in Current function) only

when the 4 705 Output at high impedånce

2.

Always sensitivity before connecting up, and increase sensitivity only when the voltages output by the DC value.

OFF, the

Voltage source and the 4 705 are close in

Voltage Source arid the 4705. A

DC

voltage source and the 4 705. A

is

preferred to ensure

DC

Voltage source do not become

cellor

set

a bank

OUTPUT

I+,

).

the null detector to its lowest

I-,

of

cells. Five points are

OFF

LED

Hi

and Lo terminals are

Hi

DC

source

is

lit. (With

lead

~pecification Verification

Report Sheet

The verification procedures in this section use the

+ Lim and - Lim facilities

. written table of tolerance limits

most cases, users will wish to verify against Reference Standards at non-cardinal values, so a table of Full Range limits would have little value.

Instead of Limit tables, a Report Sheet is provided later. This can be used for recording the results verifying any of the three stored specifications. Spaces are provided to record the displayed limits as well as the measured values. The sheet may be used as a master to generate duplicate copies for future

use.

Stored Specifications

Three specifications are stored within each 4 instrument's non-volatile memory:

24-hour accuracy, 90-day accuracy

1 year accuracy + Datron' s Calibration

+ Datron's Calibration

of

S pec mode, so a

is

unnecessary.

U ncertainty

, Uncertainty

In

of

705

]J

:n

.

'l

3.

Do

not change polarity of the 4 705 or

source without first switching the 4 705

0 FF. Care must be taken to ensure that the

ON

key

is

correct-polarity excessive voltages being connected across the null detector, particularly when checking the 4705 directly against a standard cell.

4. W ARNING

5.

CAUTION

7-2

· During Performance checks and

calibration a common mode voltage equal to the full range voltage is present at the Null Detector input terminals. ,

On

+ 1

OOOV

is

potentially lethal,. so EXTREME be . observed when making adjustments

· · sensitivity.

The N ull Detector used must be able to withstand voltages up · to 1200V between · its input terminals. Such voltages will be present 4705 is ramping from zero to _ 1000V Full Range · after setting OUTPUTON.

<luring

pressed, to avoid

checks this voltage

CAUTION must

to

DC

Voltage

OUTPUT

the null detector

the time that the

These are selectable by the CALIBRA INTERV

accessible to users by selecting 'Spec' mode (Refer to Sections 3 and 4 tolerance and limit figures which are trå.ceable to National Standards.

4700

The 'Spec' mode 24-hour accuracy limits are

computed from their specifications in Section displayed 90-day and 1-year accuracy limits for the

4705 are given at 23°C

respectively. They include Datron's calibration uncertainty, hut not the uncertainty. This should be taken· into account if appropriate.

Non-Verification

If

an instrument refer to the Routine Autocalibration in Section 8, or contact your nearest Datron Servicing Center.

N.B.

AL

switch on the rear panel, and are

).

Thus 'Spec' mode provides

Tolerance Limits

+ 1 °C and 23°C +

is

found to be out of specification,

It

is recommended

Sheets be duplicated to

use.

that

use.r'

s calibration

the Blank Report

give

copies for future

TION

6.

The

10°c

-

,--

Verification Pro·cedures

A

full

verification should be carried . out in the

sequence appearing on the Specification Verification Report Sheet. The instructions which follow are divided into 4 procedures:

DC

Voltage Full Range

DC

Voltage Linearity (lOV Range only)

DC

Current Full Range

Resistance

The displayed limits do not include temperature·-

coefficient corrections or the user' s calibration

uncertainties which should be taken into account

this

is

appropriate.

4705

DC

Voltage

Performance

CAUTION: First read the notes on the use of the

Null Detector (page 7-2).

1.

Tum

on the instrument to be checked and minimum environment. ·

2. Cancel any check that display.

of

4 hours to warm-up in the specified

MODE

cal

keys, set

is

not present on the

OUTPUT

&llow

OFF

MODE

and

if

a

Tum

to the voltage source down to zero and allow

the circuit to stabilize

N.B. When changing polarity

leads are reversed it willbe necessary to allow time for thermal effects to stabilize in the reversed connection before proceeding with the check.

5.

Full Range Checks

Press S pec Key, check each range in tum in the following order to reduce the stabilization time for thermal effects +lO0µV, +lOV;

The checks may be carried out either Range voltage or at a user's Reference standard voltage close to Full Range. the routine detailed in para Table 1 a to record the results.

6.

Linearity Check

This is performed on the lOV range. Press Spec Key. Check each pair of values in tum in the following order to reduce the stabilization time for thermal eff ects at the terminals: +lOmV, +lO0mV,

+lO0V,

at

+lmV,

_thermally.

<luring

the terminals:

+lOmV, +lO0mV, ±

+lO00V.

For

each check use

7. U se

+IV,

±lOV,

+19V.

the checks; if

at

Report Sheet

lV,

Full

I.

3.

Select Test to carry out the test routine described

in Section 4. Terminate the test routine.

DC

4. Select and N ull Detector to the 4 700

terminals as shown. Use short leads. (a) Low Voltage. lO0µV - lOV Ranges

DCVoltage

Calibration

Source

Terminals

and connect the

DC

Voltage source

Hi

and

4705

Terminals

(Remote

Sense)

Lo

The checks may be carried out either at the above values or at user' s Reference standard voltages

For

close to the above values. routine detailed in para 7. U se Report Sheet

_ Table 1 b to record the results.

·

7.

To check each value against its specification limits use the following routine: a) Null Detector Set to low sensitivity.

b)

c)

d)

e)

4705 DC

V oltage Source Set to correct polarity and

4705

Switch

voltage.

Select

RANGE

Use

to set correct polarity and

voltage on

display.

Press displayed positive . limit. Press displayed negative limit.

each check use the

OUTPUT

DC

and correct

OUTPUT

+1,

OUTPUT

+ Lim: Record the

Lim:

Record the

OFF

keys

7-3

f)

4705

g)

Null Detector

h)

4705

display

4705

Pre~s the correct-polarity ONKey. CAUTION. Pressing the wrong in approximately twice

the

being connected across

the null detector.

Increase sensitivity to

give

and use 4705 to back off to null, until the null lies between two consecutive values of the OUTPUT significant digit.

OUTPUT

Record the value closest to null and check against the specification limits.

DC Current

ON

Key·

will result

OUTPUT

an off-null reading

voltage

+ I f keys

display least-

An

output voltage of 1 V from the

full

,

now represents current, except on reduced by using an output voltage

Tum

the

DC

Voltage source down to zero and allow

the circuit to stabilize.

3.

Full Range checks

Press Spec Key. Check each range in tum, in the following order to reduce thermal stabilization time: +l00µA,

These checks may be carried out either Range current represented by a user' s Reference standard voltage. para results.

4.

To check each value against its specification limits use the following

+lmA,

For

4.

Use Report Sheet Table 2 to record the

range values

lA

range where self-heating

+l0mA,

or

at a value close to full-range

each check use the routine detailed in

DC

+l00mA,

rot1;tine:

Voltage source

of

4 705 Output

of

100m

V.

+lA.

at

is

Full

I

Performance

1.

Carry out the

3 if the

to verified.

2.

Select source, null detector and calibrated current shunt to the 4705 Do not connect

Preferred shunt values are as follows:

1 00mA range

DC

l00µA

lmA

10~

lA

DC

Voltage performance checks 1

DC

voltage performance has not been

and then I and connect the

I+

and I-terminals as shown below.

11:ull

detector to shunt yet.

range range range

range

l0kO

lkO

1000

100

0.10

DC

lmW

l0mW

l00mW

. 1 W min

lW

Voltage

min min min

min

a)

Null Detector

b)

4705

c)

DC

Voltage source Set to correct polarity and

d)

4705

e)

4705

g)

N ull Detector

Set to low sensitivity. Switch

voltage.

Select

RANGE.

UseOUTPUTkeysto_set ·

correct polarity and

current on display. Press displayed positive limit. Press displayed negative limit. Press the correct-polarity ON key and allow 5 minutes to stabilize.

CAUTION: Pressing the wrong in

.

the output voltage . being connected across the null detector.

Connect to the shunt terminal. Increase sitivity to

OUTPUT

OFF.

I and correct

OUTPUT

+

Lim:

Record the

Lim:

Record the

ON

key can result

approximately twice

DC

voltage source

se·n-

give

an off-null

7-4

]

reading and use 4 705 keys to back off to null again. Continue increasing sensitivity and backing off

until the null lies between two consecutive values the

OUTPUT least-significant digit. Ensure that the null obtained

h)

4705

OUTPUT

display

j)

Null Detector

k)

DC

Voltage source Set output to zero.

I)

4705

1.

Carry out the

1 to 3

verified.

2.

For checks are required: a)

b) Local Sense (2-wire) at Full Range (Resistor c) The displayed values were obtained at the most

recent calibration, except zero and Full Range in Local Sense which are the same as in Remote Sense.

Resistance Performance

DC

if

the

DC

Voltage performance has not been

each resistance

Remote Sense ( 4-wire) at Full Range

(Resistor Value

plus intemal wiring). ·

Local Sense (2-wire) at Zero (interna! wiring only).

Record the value closest to null and check against the specification limits.

Set to low sensitivity. Disconnect from the shunt terminal.

Switch

Voltage performance checks

(RANGE)

).

is

stable.

OUTPUT

selection, three

1

0Mn

and 1

display

OFF.

00Mn

+ I t

of

calculated directly from the specification figures in Section 6 and are not modified by accuracy derating factors. The displayed limits refer to the 90-day Accuracy specification. The Stability specification should only be referred to, when checking against the same standard used for the previous calibration.

4. Press

Perform each check in the following order:

· and I-Terminals, voltage measurement across

Spec Key.

Carry out the checks in the order listed in Table (Resistanc~) on the Verification Report Sheet, to minimize waiting time for thermal stabilization.

Set 4705 Select resistor value Zero press Select

OFF).

Record Press Press Connect measuring equipment (2-wire to

Lo Terminals, or 4-wire energizing current to Hi and Lo Terminals).

Set 4705 Measure Resistance value and record on Table Check that this value is between + Lim and - Lim values recorded. "

OUTPUT OFF.

(RANGE

OUTPUT

Local/Remote Sense ( 0

OUTPUT

+Lim

-Lim

3.

and record value on Table 3. and record value on Table 3.

OUTPUT

Zero Key).

displayed value on Table 3.

ON.

Key).

UTPUT

(If

Local

must be

Hi

3

and

I+

3.

For

each verification check, the measured value

should lie between the 90-day specification limits

taken about the displayed value. The upper and

lower test limits should be determined using Spec mode and secondary modes

-Lim,

switch on the rear panel set to 90-day ( see Section 4 for operation record these limits,

(Resistance) on the Specification Verification

Report Sheet.

N.B.

currents will be used to verify the resistance specification, so· the displayed limits have been

with the CALIBRATION INTERVAL

of

Spec mode). Space to

is

reserved in Table 3

It

is

assumed that the specified energizing

+Lim

and

7-5

_/

[

-,

Ti

Jj

..

THIS

....

HIGH VOLTAGE

INSTRUMENT

·

OF

A

llTHAl

·oANGIR.

IS CAPABLE

DELIVERING

EllCTRIC

SHOCK

I

[7]

7]

[·

]]

-

'

i I

(i

r-:

.]

5

..

...

Unless

it

DO

I+

I-

and terminals

,

It

your

you

is safe

NOT

Hi

or

Guard terminal is sensitive voltage

can

instrument!

are sure

to

do so,

TOUCH

to

over -

damage

that

the

Lo leads

5

rr

11

7-6

DANGIR

I I

~

I

ul

MODEL 4705VERIFICATION REPORT SHEET.

(Use as master for duplicate copies)

_______________

Serial Number Checked by

________________

_

Date

Company/Dept.

_____________

RS1

__._

__

_

Note: 1 . The comparison between

1 a.

first been nulled out.

2.

DC Current & Resistance table on reverse

DC

Voltage

Full Range Checks

Polarity/ DC Calibration Spec Mode Limits OUTPUT display

Range

100µ.V

+

-

100µ.V

1mV

+

1mV

-

10mV

+

-

10mV

100mV

+

-

100mV

1V

+

-

1V

10V

+

-

10V

100V

+

-

100V

+1000V

-1000V

Source Voltage

OUTPUT

display readings for null and the Spec Mode Limits is Valid it zero errors have

+Lim

-Lim

,

reading for null

J

b.10V

Range Linearity

Polarity/

nominal value Source Voltage

10mV

+

-

10mV

-

100mV 100mV

+

1V

+

-

1V

-

10V 10V

+

19V

+

-

19V

DC Calibration Spec Mode Limits

+Lim

-Lim

OUTPUT display

reading for null

7-7

···-

--·---

-----------~----------

2

DC

Current: Full Range Checks

Polarity/ Shunt

, Range

100µA

+

100µA

-

1mA

+

-

1mA

10mA

+

-

10mA

100mA

+

-

100mA

1A

+

-

1A

3 Resistance: Value Measurements

Range/Sense

100Mn Remote

LocalZero 10Mn

LocalZero

1MO

- LocalZero 1ookn

LocalZero 1okn

LocalZero 1kn

LocalZero 100n

LocalZero

i

:

10n

LocalZero

Value

Local

Remote Local

DC

Calibration Spec Mode Limits OUTPUT display

Source Voltage

Specified

Current Used

1µA

10µA

100µA

1mA

10mA ·

10mA

+Lim

Method used

Current Displayed

Value

-Lim

___________________

SpecMode Measured

+Lim

-Lim

reading for

Value

nu11

·

_

7-8

I

AC Specification Verification

Choice of Verification Method

The wide dynamic range of the 4705 makes it

necessary to employ diff erent verification methods

· for different groups of . output and frequency ranges.

For

instance: The most common method of verifying

AC Voltage outputs is to check against an accurate

DC

Voltage Standard via a Thermal Transfer.

However, available thermal transfer standards are

not suitable for direct verification of the millivolt

ranges, because their transfer elements are

insufficiently sensitive. Naturally, the range, accuracy and traceability of

users' standards governs the degree to which the performance of any new equipment can be verified.

of

This is especially true for the 4705, in view range of the parameters to be checked.

This section describes a recommended method of verifying each ofthe parameters listed below. Where appropriate, alternative methods are described in

. Appendices to the section.

Parameters to be Verified, with Recommended Methods

The following list of parameters is grouped

according to the type of equipment suitable for

verification.

the

is

An alternative method for users in possession

lO0kHz) Inductive Voltage Divider

3. Current Ranges (1mA to 1A).

a.

1 0mA, 1 00mA and 1 A Full Range values are checked using a Thermal Transfer Standard fitted with standard shunts at and

HF,

against a

and

b.

The 1 mA Full Range value can be checked using the same method, provided that lowcurrent shunts for the thermal transfer standard are available.

Alternatively, if calibrated available., the Current Ranges can be verified by voltage measurement, using an

described in Appendix

Fixed or Adjustable Voltage Standard?

Many users who are able to verify Current to the accuracy required for the 4705, will also have access to an adjustable

as

Standard be verified at cardinal values. DC

Voltage Standards only, the 4705 can be

verified at non-cardinal values directly or by using the 4 705 'Error Mode'. In both cases users will need to calculate the effects uncertainty, so calculations for total tolerance limits

are given in Appendix 4.

Reference.

described at Appendix 2

of

a ,Wideband (to

(WIVD).

DC

Current Standard.

AC

current shunts are

AC

DVM,

3.

AC

Voltage and

DC

Voltage

In

these cases their 4 705 can

For

users with fixed

of

their own Standards'

LF

as

1. Voltage Ranges

a.

Full Range values are verified at by direct thermal transfer against a Voltage Standard.

and

b.

Instrument Linearity and 19.0000V on the lOV range at LF, using the same method.

2. Millivolt Ranges

Full Range values are verified

a.

At LF:

Commercially available Inductive Voltage

Divider (IVD) -and standardized DVM

Transfer. (Such IVDs are normally only suitable for 5kHz).

and

b.

at HF:

· A 100% to 10% of Range Transfer method,

after verifying 1 0V range

HF

1 V standardized and corrected for linearity error, then used as a transfer standard. The

method

(1

V to

1000V)

(1

mV to 1

LF

verification, up to about

Full Range value. A DVM

is

described later in this section.

is

verified

OOmV).

as

HF

LF

and

at 1 V,

follows:

linearity and

HF DC

lOV

is

Summary of Equipment

Requirements

This summary relates to the recommended method of verifying the 4 705. Alternative methods, with the required equipment, are described in appendices.

AC VOL TAGE ( 1 V - 1 000V Full Range Values and

lOV Range Linearity)

An

Adjustable

accuracy.

Example:

Datron 4000 or 4000A Autocal Standard.

AC/DC

An of operating over the range 1 V to

AC MILLIVOLTS

(lmV -l00mV

DC

Voltage Source of suitable

Thermal Transfer Standard capable

11

00V RMS.

Full Range Values)

7-9

at

LF:

A commercially-available Inductive Voltage

1,

Divider tapped at 10: suitable accuracy and frequency response.

100: 1 and 1000: 1

of

Transfer, and its displayed voltage is recorded and

checked against the, tol~rance limits. · See Appendix 1 for the procedure.

at HF:

The 4 705 under test with the correction figure for 10% of its 1 0V Range at

The

DC

Voltage Source used for 1 V - 1 000V

ranges.

and at both

The

AC/DC

1 000V ranges.

· . A D VM response.

Example:

Datron 1081 or similar.

AC

CURRENT

DC

A

AC/DC

an of Calibrated Thermal Transfer Current Shunts _suitable

·

For

the alternative method at Appendix 3, a set calibrated and accuracy.

LF

and HF:

Thermal Transfer used for 1 V -

of

suitable accuracy and frequency

(lmA-

Current Source of suitable accuracy and

Thermal Transfer together with a set

accuracy.

AC

Current Shunts of suitable value

HF.

lA

Full Range Values)

of

Summary of Verification

Procedures

1. Full Range Voltage

Adjustable DC Standard

The 4 705 Range voltage · at Thermal Transfer is nulled against the 4 705 Full · Range voltage. The with the Thermal Transfer, and its output voltage recorded. Its uncertainty Tolerance Limits calculated. The the

DC

Details of the procedure are on page 7-12.

Fixed DC Standard

The Thermal Transfer Standard, and its fixed · voltage Rep9rt Sheet. The 4705 this voltage, the and the output voltage

is

connected up and set to output a Full

voltage

Tolerance Limits are calculated. The 4705

is

within the tolerance limits.

S pec Mode tolerance

is

adjusted to null with the Thermal

(1V-

~e

required frequency. The

DC

Standard

is

OUTPUT display

1000V

is

adjusted to null

is

also recorded, and the

4705 is verified if

nulled · against _ the

is

recorded on the

is

Ranges)

DC

is

set to

recorded,

2. Linearity ( Performed

This should be checked at in tum, or at user' s Reference standard voltages close to the above values. Similar techniques are used as for Full Range voltages. results are recorded.

See page 7-12 or Appendix 1 for the procedure.

3. Full Range Voltage

Method 1

At

LF,

the 1 V Full Range value is first verified using thermal transfer, then this voltage is divided via the standard IVD to standardize an

millivolt Full Range value. The 4705 millivolt range

is

then verified at this standardized value by

measurement.

See page 7-13 for the procedure.

. .

At H

F,

the 4 705 is set to the 1 0V Range. Outputs are measured at 1 0V and 1 V using thermal transfer, and a linearity correction factor is calculated for the 1 V output. . . The 1 V Range is selected with output set to 1

HF.

at correction factor and the output standardize the

The 1 00m V Range is selected at and the output measured on the DVM. The 1 00m V

Full Range value verifies if the corrected value, plus or minus the specified tolerances.

The 1 00m V Range, and used to verify Range verify the

See page 7-14 for the procedure.

Method 2

At

verified using thermal transfer, then this voltage is

divided via the wideband IVD to standardize an DVM millivolt range value by

See Appendix 2 for the procedure.

The output setting

AC

DVM.

DVM

both

is

standardized again åt lOmV on the

in-

the same way. The process is

lmV

Range. ·

LF

and

HF,

the 1 V Full Range v~lue is first

at the millivolt Full Range value. The 4705

is

then verified at this standardized

D

VM

m~asurement.

on 1 OV

lV,

(1

mV

Range)

l0V

and 19.0000V

For

each check the

- 1

OOmV

AC

is

changed by the

HF

DVM

Ranges)

DVM

is

used to

Full Range,

reading is the

tp.e 1 Om

repe<:tted

at the

DVM

00m

V Full

to

AC

V

. '

I

[:

-77

C

~

C,.

JJ

__

,·

I

[

---

7-10

a

4. Full Range Current

(us.ing

Standard Shunts)

The Thermal Transfer Current Shunt is fitted to the

of

Shunt lnput

the Thermal Transfer Standard and the 4 705 set to output a Full Range current int~ the shunt at the required frequency. The output current is

split between the · shunt and the transfer element. This is compared with the output from a Standard DC

Current Source.

See Page 7-18 or Appendix 1 for the procedure.

Alternative M ethod

1

The 4 705 is connected up and set to output a Full Range current into the calibrated at the required frequency. The

AC

Current Shunt

4705 Current output

develops a voltage across the shunt which is measured by the

,·

load the shunt. The procedure is detailed in Appendix

AC DVM, with care taken not to

3.

·Specification Verification Procedures ·

Preparation

· Before attempting any verification ensure the following steps are carried out.

1.

Tum

on the instrument to be checked and allow a

of

minimum

2 hours to warm-up in the specified

environment.

2. Ensure familiarity with normal operation as described in this Handbook.

Index of Recommended Procedures

( using adjustable

Voltage Ranges ( 1 V to 1 000V)

a.

Full Range Values

b.

Instrument Linearity ( 1

DC

Voltage Standard)

0V

Range)

Page

7-12 7-12

3. Cancel any

0

FF

and check that 'cal'

MODE

display.

Keys, ensure

is

(If

'cal'· is present,

OUTPUT

not present on the

tum

Calibration Keyswitch on the Rear Panel to its

RUN

4. Self-Test: select described in Section

position).

Test

to carry out the test routine

4.

Terminate the test

routine.

·

'5:

Consult the manufacturer' s handbooks before connecting and operating any equipment in the measurement system.

6. Interconnections and Guarding: Refer to Section 4 page 4-1.

7. Select 24hr, 90dy or 1 yr on the

CALIBRA

TION

INTERVAL Switch. Refer to Section 4 page 4-10.

the

Millivolt Ranges ( 1 m V to 1

a.

LF

b.

HF

Current Ranges ( 1

Report Sheet Alternative Procedures As Recommended hut using Fixed

DC

Voltage Source ( with Report Sheet RS3) . 1

· Millivolt Checks using Wideband Current Checks using Calibrated Total Tolerance Limit Calculations Uncertainty and Traceability General Procedural Information Harmonic Distortion Measurement

mA

RS2

00m

to 1 A)

V)

IVD

AC

7-13

7-14

7-18 7-19

Appendix

2

Shunts 3

4

5

6 7

7-11

AC Voltage Verification Procedure

(U

sing Adjustable

Record Results on Report Sheet RS2 (page 7-19)

Full Range

DC

Checks

Voltage Calibration Standard)

(1

V - 1

OOOV)

,

r::::

:

[[

[:

I

DC

Voltage Calibration Standard

-----•~oc

I

WARNING THE TERMINALS MARKED WITH THE -

SYMBOL CARRY THE OUTPUT OF THE

4705. THESE TERMINALS OTHER CONNECTIONS UNDER VOLTAGES. UNDER NO CIRCUMSTANCES SHOULD USERS TOUCH ANY OF THE FRONT (OR REAR) PANEL TERMINALS UNLESS THEY ARE FIRST SATISFIED THAT NO DANGEROUS VOLTAGE IS PRESENT.

a.

With

Standard to the Thermal Transfer 4-wire conriection and Remote Sense available.

TEST COULD CARRY LETHAL

OUTPUT

OFF, connect the

AND

TO

THE LOAD

DC

"-..

ANY

,Voltage

input. U

~~

se

if

Thermal Transfer Standard

...

·

I

AC....,.,..

___

_

4705to Calibrated

be

I

j. Sum the Verification setup uncertainties . and

record in the U s column as voltage deviations.

(Refer to Appendix 5).

For Total Tolerance Limit Calculations refer to

Appendix 4 page 7-31, para

k.

Calculate the Lower and Upper Total Tolerance Limits. Use Calculation A calibrated by Datron.

Use Calculation B ifthe 4705 was last calibrated

against the standards being used for

verification.

1.

Each 4 705 Full Range output Voltage outputs recorded in (g) are at or between the corresponding Total Tolerance Limits.

1.

.

if the 4705 was last

is

verifiedif the

DC

[I

[

b.

With

OUTPUT Thermal Transfer AC input. Use 4-wire connection and Remote Sense.

c.

Configure the Thermal Transfer for measurement at the required voltage.

d.

Set the 4705

Frequency (see Report Sheet RS2) . ·

e.

Set 4705

Transfer to the 4705 AC

f.

Configure the Thermal Transfer for nulling.

g.

Configure the required voltage, set its its output to null the Thermal Transfer. Record its

output voltage on Report Sheet RS2.

h.

Repeat ( Sheet RS2 Table l(a).

7-12

OUTPUT

c)

OFF, connect the 4705 to the

OUTPUT

DC

to (g) for all 4 705 outputs on Report

Range, Voltage and ·

ON, ·and null the Thermal

OUTPUT.

Voltage Standard at the

OUTPUT

ON and adjust

AC

DC

Linearity

(l0V

Range)

m.If the

operations (

Tablel(b).

n.

Ifthe 1 Millivolt verification and verification.

lOV Range verifi~d correctly, repeat

c)

to (g) for Report Sheet RS2

Vand

l0V

Ranges verified, proceed to

AC

Current

Millivolts (LF) Verification Procedure

I

(Using verified 4705 1 V Range, Inductive Voltage

Divider (IVD) and Record results on Report Sheet RS2, Table 2(a) (Page 7-20

).

AC

DVM).

a.

With and

DVM

to

1:

10 and the

OUTPUT

4705AC

already

Verified

4705ACmV

R,anges

Verified Lo

OFF, connect the 4705, IVD

1V

Remote

Standardization

Verification

to

Sense

be

for Standardization. Set the IVD ratio

AC

DVM

to measure 100m

Hi

"j

of

,

of

-------,,

4700 L F

V.

----

DVM

~

AC

DVM

(mV

Ranges)

Millivolt

Ranges

AC

DVM

_______

Ranges

(mV

Rangesi

--J_

I

j. Sum the Verification setup uncertainties and

record

in

the U s column as voltage deviations.

(Refer to Appendix 5).

J

b.

Set 4 705 to 1 V Range, 1 kHz, and adjust for corrected 1.000000V output.

c.

Set 4705 reading as

·

d.

Set 4705

OUTPUT

Vl.

OUTPUT

ON

and note the

OFF, and reconnect the test

circuit for Verification.

e.

Set the 4705 adjust the

f.

Set 4705 OUTPUT

g.

Record the 4705

_last

column

h.

Repeat ( a) to (g), hut setting the 4 705, IVD ratio and D VM as required to verify the 1

OUTPUT

+

1,

keys for a

OUTPUT

of

Report Sheet RS2 Table 2(a).

RANGE

to lO0mV and

Display to 100.0000m

ON

and adjust the

DVM

reading

Display setting in the

Om 1 m V Full Range outputs; still using the corrected 1 V Full Range output in (b

).

Record the results on

Report Sheet RS2 Table 2(a).

DVM

V.

of

VI.

V and

Total Tolerance Limit Calculations Refer to

Appendix 4 page 7-31 , para

k.

Calculate the Lower and Upper Total Tolerance

1.

Limits: Use Calculation A ifthe 4705 was last calibrated by Datron. Use Calculation

B ifthe 4705 was last calibrated

against the standards being used for verification.

1.

The 4 705 m V Full Ranges are verified if each the 4705

OUTPUT

Display settings recorded at

of

(g) are at or between the corresponding Total Tolerance Limits.

7-13

Millivol,ts (HF) Verification Procedure

(Using verified 4705 Range Correction Factor and results on Report Sheet RS2, Table 2(b) (Page 7-

20).

Full Range Checks

N.B. These verification checks,are not full traceable. The verified output values

and

l0V

on the 4 705 linearity error at 1 V on the 1 0V range. From the linearity measurement a 10% and Scaling F actor This fäctor output setting at 10% DVM

lnterconnections

PIG

is

subsequently used to correct the 4705

for verification

1 (lOV and 1 V Ranges)

AC

1 V and lOV Ranges, 10%

AC

DVM) Record

(1

mV

- 1 OOmV

of

1 V on the 1 V Range;

l0V

Range are used to measure the

'C'

is

derived.

of

r.ange,

of

the next range down.

at

1 OOkHz)

of

range Linearity

to standardize a

All

outputs

Remote

Local Guard

FIG 2 (l00mV

All

outputs at 1 MHz,

Local Guard

4705

Sense

to

4705

at

1 MHz , and

lmV

Ranges)

I

0.N/C

I

0N/C

600mm Uniradio

M70 (75a/67pF/m)

'

/

600mm Uniradio

'

M70 (75n/67pF/m)

1V

Range

Local Guard

4-wire

,100mV

Range Local Guard 2-wire

7-14

]

I

l

]

l

]

Stage 1 Derive the Linearity and Scaling Factor

as

follows: ( C

0.1):

a.

Ensure that the Millivolts (LF) Verification has been completed.

Ensure- that the 4705 has been verified at

lOV

and 1 V HF(lO0kHz)Full Range (page

7-12

).

Record the measured values asfollows:

4705 lOV

Actual output voltage 4705 1 V

Actual output voltage - 'V2'

b.

Calculate 1 V correction 'V3' = 1

c.

With

OUTPUT 4705 terminals using the exact 4-wire connections as_in Pig.

measure AC on its 1 V range.

d.

On 4705, select the 1 V range and Remote Sense. Set

FREQUENCY

Set O

UTPUT

Set

OUTPUT reading Set

as

OUTPUT

is

a number of value close to

FR

setting - 10.000,00V

'Vl'

FR

setting - 1.000,000V

OFF

connect a DVM to the

1.

Set the DVM to

to

lMHZ.

display reading to

ON, and note the DVM

'Vt'.

OFF.

V2

V3.

'C'

Record in 5 ½ digits resolution

Vl=

V2=

V3=

Vt

is

a transfer value

e.

On 4 705, select the Sense). Set 4705 Set Adjust the reading of Vt.

f.

Note the 4705 'V4'. Set

g.

From the values

1 0V range linearity correction and scaling

factor

OUTPUT

'C'

as

follows:

ON.

OUTPUT

OFF.

C

lOV

range (Remote

display reading to 1

display for a DVM

display reading

Vl

and

V4

calculate the

=

Vl x V4

100

V.

as

Vt=

Record in 5 ½ digits resolution

V4=

Calculate in 5 ½ digits resolution

c=

I

7-15

L

Stage 2 To Verify the

Output

a.

Ensure that the 4705 terminals as shown

b. Set the 4705 to the 1 V

Calculate the value 'V3 x C'.

Set

OUTPUT

c.

Set the

d.

Set 4 705

settle. Note the

e.

Set4705 DVM shown in Fig. 2.·

f.

Set 4705 to its lO0mV (Remote Sense is automatically deselected.)

Set Adjust the 4705 Output ofV(lO0t). setting as 'V(lO0m):

to the 4705 terminals in 2-wire as

OUTPUT

100mV

DVM

display to this value.

DVM

to measure lO0mV.

OUTPUT

DVM

OUTPUT

ON.

Notethe4705

AC Range Full Range

is still connected to the

in

Fig.

1.

AC

range.

ON,

allow the output to

reading as 'V(lO0t)'.

OFF

andreconnectthe

AC

range.

fora

DVM

OUTPUTdisplay

reading

Calculate in 5

I

V3xC=

V(l00t)

I

V(lO0t)=

Record in 5 ½ digits resolution

.1

V(I0Om) =

½ digits resolution

is a transfer value

L

[I

J

~

Il

[

i,

c-

Record this setting in the last column table 2 (b).

Stage 3 To Verify the 1

Output

a.

Ensure that the 4 705 terminals as shown in Fig. 2.

b.

Ensure that the 4705 AC

range. Calculate the value 'V( 1 00m) x C'. Set

OUTPUT

c.

Set the

d.

Allow the output to settle.

Note the

e.

Set 4705 to its lOmV Adjust the 4705 Output ofV(l0t). setting as 'V(lOm)'.

DVM

Note the 4705 OUTPUT display

Om

V AC Range Full Range

DVM

is still connected to the

is

set to the lO0mV

display to this value.

to measure lOmV.

reading as 'V( 1 0t)'.

AC

range.

fora

DVM

of

RS2

reading

Calculate in 5

V(lO0m) x

V(l0t)

Record in

V(lOm) =

C=

is

=

4½

[:_

½ digits resolution

a transfer value

digits resolution

7-16

Record this setting in the last column table 2(b).

of

RS2

a

Stage 4 To Verify the 1

Output

a.

Ensure that the DVM is still connected to the

4705 terminals as shown in Fig.2.

mV

AC Range Full Range

Calculate in

4½

digits resolution

b.

Ensure that the 4705

is

set to the

range.

Calculate the value

OUTPUT

Set

c.

Set the DVM to measure lmV.

d.

Allow the output to settle.

'V(l0m)

display to this value.

x C'.

Note the DVM reading as 'V(lt)'.

e.

Set 4705 to its Adjust the

lmV

AC range.

4705 Output to

give DVM reading of V(lt). Note the

4

705

OUTPUT

display setting

. 'V(lm)'.

Record this setting in the last column table 2(b). ·

Stage 5 Verification Against Limits

For Total Tolerance Limit Calculations

Refer to Appendix 4 page

7-31

para

l0mV

1.

AC

a settled

as

of

RS2

V(lOm) x

V(lt)

V(lt) =

Record in

V(lm) =

C=

is

a transfer value

3 ½ digits resolution

a.

Sum the V erification setup uncertainties and record in the Us column ofRS2 Table 2(b) as voltage deviations. (Refer to Appendix 5).

b.

Calculate the Lower and Upper Total

Tolerance Limits:

Use Calculation A

if the 4705 was last

calibrated by Datron.

Use · Calculation B if the 4705 was last

calibrated against the standards being used

for verification .

.

c.

Each 4 705 m V Full Range (HF) is verified if

4705

the

OUTPUT display settings V(lOm) and V(lm), recorded in the last columnofRS2 Table2(b), are atorbetween their corresponding Wideband Calculated Tolerance Limits.

V(lOOm),

7-17

AC Current Verification Procedure

(U

sing Thermal Transfer, Current Shunts and

Current Standard). Record results on Report Sheet RS2, Table 3 (Page 7-20

).

DC

Full Range Checks

a.

With 4705 AC

and then I, OUTPUT Frequency

b.

Configure the Thermal Transfer for 1 0mA Current measurement and connect the appropriate shunt.

c.

With

I---:

terminals across the Shunt.

d.

Set 4705 Transfer to the 4705 Set 4705

e.

With

Standard for an output across the Transfer Shunt.

f.

Set the

output current to null the Thermal Transfer. Record its output current on Report Sheet RS2 Table3(a).

OUTPUT

of

OUTPUT

DC

Standard

(1

mA - 1A)

4705 under

Verification

DC

Current Calibration Standard

OUTPUT

Display to 10.00000mA at a

300Hz.

OFF, connect the 4705 I+ and

OFF, configure the

AC~

-0-

DC!_/

OFF, set the Function to

RANGE

ON, and null the Thermal

AC

OUTPUT.

OFF.

of

1 0mA, and connect

OUTPUT

ON

to 10m,

DC

Current

and adjust its

Current

I

Transfer Switch

I

--

Shuntlnput with Shunt Fitted

Thermal Transfer Standard

I

j.

If

the Thermal Transfer has been adequately calibrated for 1 mA transfers, repeat ( a) to 4 705 1 mA Full Range outputs, recording the Standard output currents in Report Sheet RS2 Table 3(b).

k.

Sum the Verification setup uncertainties and record in the (Refer to Appendix 5).

For Total Tolerance Limit Calculations

refer to Appendix 4 page

1.

Calculate the Lower and Upper Total Tolerance Limits. Use Calculation by Datron. Use Calculation against the standards being used for verification.

m.Each 4705 Full Range output verifies if the

Current outputs recorded in ( the corresponding Total Tolerance Limits.

U s column as current deviations.

7-31

Para

1.

A ifthe 4705 was last calibrated

B ifthe 4705 was last calibrated

f)

are at or between

(g)

for

DC

g.

Set 4705 Frequency to 5kHz, and repeat (c)

to

(f).

h.

Repeat (a) to (g), but for 4705 lO0mA and Full Range outputs.

7-18

lA

MODEL

RS2

-For Users

Serial

Number

with

______________

4705

Adjustable

VERIFICATION REPORT SHEET. RS2

DC

Voltage Standards.

Date

Checkedby

Note: -On

1.

AC

a.

1Vto

OUTPUT

RANGE/

FREQUENCY Voltage

1V

10V

10V 100kHz 10.0000V 9.9954

100V 1kHz

100V 100kHz

1000V

_____________

receipt of the instrument it

VOLTAGE (Using Adjustable

1000V Ranges.

4705

1kHz 1.00000V .99965 1.00035 0.00013V

100kHz 1.00000V .99954

1kHz 10.0000V 9.9965 10.0035

1kHz 1000.00V

30kHz 1000.00V

4705 Wideband

Nominal

OUTPUT

100.000V

Lower(Lr) Upper(Ur)

(

99.965

99.954

999.65

999.54

_

Company/Dept.

is

recommended

DC

Voltage Standard via Thermal Transfer)

Relative Accuracy

Tolerance Limits Uncert'y Uncert'y

1.00046

10.0046 0.0115V

100.035 0.013V

100.046 0.020V

1000.35

1000.46 0.25V

to

checkat the frequencies

Datron User's Wideband Calculated Total

Cal.Std.

±Ud(Abs)

· 0.00115V

0.0013V

0.17V

Cal.Std.

±Us(Abs)

_________________

shown

below.

Tolerance Limits

Lower

Upper

User's

DCStandard

valuefor

Null

_

J

b.

Linearity (Performed

1kHz 1.0000V

10V

1kHz

10V

10.oboov

1kHz 19.0000V

on 1 OV

0.9987

9.9965

18.0040

Range)

1.0013 0.00013V

10.0035 0.0013V

19.0060 0.0026V

J

7-19

[

2.AC MILLIVOLTS

a.

LF 1 kHz

100mV

10mV

1mV

b.

HF

100mV 100.0000rriV 99.894

10mV 10.0000mV

1mV 1.0000mV .989

3.

AC

a.

10mA

(using Verified 1 V Full Range, lnductive Voltage Divider and

4705 4705 Wideband Datron User's Wideband Calculated Total

OUTPUT

RANGE

100.000mV

10.000mV 9.986

1.000mV

100kHz

(Using Verified 1 V and 1

CURRENT

to

1A

Ranges. (Using.Thermal Transfer, Current Shunts and

1mVto

Nominal Relative Accuracy

OUTPUT Tolerance Limits

Voltage

100mV

Lower(Lr) Upper(Ur)

99.953

.990

9.980

Ranges

100.047

10.014

1.010 0.010mV

OV

Full Range, 10% Range Correction and

100.106

10.020 0.017mV

1.011

AC

DVM)

Cal.Std. Cal.Std. Tolerance Limits Uncert'y Uncert'y

±Ud(Abs)

0.035mV

0.013mV

0.067mV

0.012mV

±Us(Abs)

l..ower

AC

DC

Current Standard)

DVM)

Upper

4705

OUTPUT

Display Setting,

4705

OUTPUT

RANGE,

F.REQUENCY

300Hz 9.9962 10.0038

10mA

10mA 5kHz 9.9949

100mA 300Hz

100mA 5kHz

1A 300Hz .99944 1.00056 0.00029A

1A 5kHz

b. 1 mA

Range. (It Thermal Transfer is calibrated at this level)

1mA 300Hz

1mA 5kHz

Transfer

Shunt Relative Accuracy Cal.Std. Value Tolerance Limits Uncert'y Uncert'y

Wideband

Lower(Lr) Upper(Ur)

10.0051

99.962

99.949

'

.99925

.99962

.99949 1.00051 0.00026mA

100.038

100.051 0.026mA

1.00075 0.00044A

1.00038 · 0.00026mA

Datron

±Ud(Abs)

0.0026mA

0.026mA

User's Wideband Calculated Total

Cal.Std.

±Us(Abs)

Tolerance Limits

Lower

Upper

User's

DC Standard

våluefor

Null

7-20

Appendix 1 to:

4705 User's Handbook

Section 7

]I

APPENDIX VERIFICATION

,flXED

DC VOLTAGE

1 ·

PROCEDURES FOR USERS

STANDARDS

AC Voltage Verification Procedure

(U

sing Fixed Voltage

Record results on,~eport Sheet RS3 (Page 7-25).

Full Range

Checks

DC

(1

V - 1

DC

Voltage

Cal

ibration

Standard

Calibration Standard).

OOOV)

I

•

DC

Thermal Transfer Standard

I

WARNING THE TERMINALS

~

THE 4705. THESE TERMINALS OTHER CONNECTIONS UNDER

VOLTAGES.

SHOULD FRONT (OR REAR) PANEL TERMINALS UNLESS THEY ARE FIRST SATISFIED THAT NO PRESENT.

a.

· available. b.

c.

d.

e.

SYMBOL CARRY THE OUTPUT

TEST COULD CARRY LETHAL

UNDER

USERS

DANGEROUS

With

OUTPUT

Standard to the Thermal Transfer

4-wire connection and Remote Sense if

With

OUTPUT Thermal Transfer connection and Remote Sense.

Configure the Thermal Transfer for measurement at the required voltage.

Set the voltage, Transfer to its output. Record its output voltage on Report Sheet RS3 Table Voltage'.

Configure the Thermal Transfer for measurement at the required voltage.

DC

Voltage Standard to the required

OUTPUT

l(a)

as '4705 Required

MARKED

NO CIRCUMSTANCES

TOUCH

OFF, connect the

OFF, connect the 4705 to the

AC

input. U se 4-wire

ON,

and null the Thermal

WITH THE

AND

TO

THE LOAD

ANY

VOLTAGE IS

OF

DC

input. U se

OUTPUT

Voltage

OF

ANY

THE

DC

AC

f.

g.

h.

j;

k.

I.

Total Tolerance Limit Calculations

See Appendix 4 page

m.Calculate the Lower and Upper Total Tolerance

WITH

.

AC

I

...

4705

under

Verification

I

Set 4705

0

UTPUT

Transfer. Record

Null' on Report Sheet RS3 Table l(a).

Ensure that the 4705 CALIBRATION INTERV

Spec key and record the

in ppm as canceL

Obtain the Datron Calibration Uncertainty from

Section ppm'.

Repeat ( c) to

4705 outputs on Report Sheet RS3

Table l(a).

Sum the Verification setup uncertainties and record as (Refer to Appendix 5).

Limits. Use Calculations A and C if the 4705 was last calibrated by Datron.

se

Calculations B and C if the 4 705 was last

U calibrated against the standards being used for verification.

OUTPUT

Display reading to null on the Thermal

the'4705

AL

'±Ur

6 for the 4 705 output, and record

'+

OUTPUT

switch is set to 90dy. Press the 4705

ppm'. Press the S pec key again to

G)

for required voltages close to all

U s ppm'.

7-31

ON,

MODE

and adjust its

Display Reading for

Display reading

Para

2.

as'+

Ud

7-21

Datron 4705 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual