HP 412A, 412AR Operating And Service Manual

I.

:

HP

..

.

This vintage Hewlett Packard document was

preserved and distributed by

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www.

'

Please visit us on the web

..

On-line curator: Tony Gerbic

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i

(r,

,'

a

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i

f

DC

OPERATING

(HP

MODEL

VACUUM

SERIALS

PREFIXED: 301-, 3160, 424-,

AND

PART

SERVICE

NO.

00412-90003)

412A/AR

TUSE

MANUAL

VOLTMETER

I

649-

P.

1

i

OOT29-5

Copyright Hewlett-Packard

0.

Box

301,

Loveland,

Colorado,

Company

80537

1961

U.

S.A.

Printod:

NOV

1968

0

h

Model 4 12A

TABLE

OF

CONTENTS

Table

List

of

Contents

of

Tables

I

i

1

Section Page

I

GENERAL INFORMATION

1.1

.

Introduction

1.7

.

Specifications

1.Y

.

instrument and Manual Identification

.

Section

.

?

11

INSTALLATlON

2.1

.

Introduction

2.3

.

Initial inspection

2.5 . Power Requirements

2.7 . Grounding Requirements

2.10 . lnstallatiori

2.13

.

Repackaging

Section Page

I11

OPERATING INSTRUCTIONS

3.1

.

Introduction

3.3

.

Low-Level Electrical Phenomena

3.7 . Turn& Procedure

3-8

.

Voltage Measurement

3.9

.

Y

Section Page

IV

Current Measurement

3-1

0

.

Resistance Measurement

3-1 2

.

Amplifier Operation

THEORY

4.1 .

4.3 . Block Diagram Analysis

4.5.

4.7

4.9

4-1

OF

General Range and Function Selection 4-1

.

Filters

.

Modulator. Amplifier. Demodulator.

and Chopper

1

.

Cathode Follower and Polarity Selection

.........................

........................

..........................

.........................

..........................

for

.........................

OPERATION

.............................

..............................

........................

.................

.....................

...................

...............

Shipment

..............

...............

.........

....................

..................

................

...................

..................

................

...........

.....

Page

...

1-1

I

-I

1-1

2-1 2-1

2-1

3-1 3-1

3-1

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

3-3

4-1

Section page

V

MAINTENANCE

5.1

.

lntroduction

5.3

.

Required Test Equipment

5.5

.

Performance Checks

5.7

.

Meter Zero

5.10

.

Voltmeter Accuracy Check

5-1

1

.

Milliammeter Accuracy Clieck

5-1

2 . Ohmmeter Accuracy Check

5.13 . Input Kcsistance Clieck

5.14

.

AC Kejection Check

5.15

.

Adjustment and Calibration Proccdure

5.17 . Cabinet Removal

5.18 .

5.20

5.21 . Cathode

5.22 . Meter Electrical Zero Adjustment

5.23

5.24

5.25

5.27 . Front Panel Indications

5.29 . Power Supply and Amplifier Checks

5.33 . Modulator Clieck

5.34

5.36

5.37

5.39

541

546 . Input Cable Keplacemcnt

Section Pap

VI

REPLACEABLEPARTS

6.1

64

6.6.

Section l’ilgc

VI1

CIRCUITDIAGRAMS

7.1

Mechanical Adjustment of Meter Zero

.

Hum Balance Adjustment

Amplifier Gain Adjustment and

.

Meter Calibration

Olimmeter Adjustment

.

Troubleshooting

.

Modulator Replacement

.

Demodulator Check

.

Demodulator Replacement

.

Switch Checks

.

Adjustment

Components

.

lntroduction

.

Ordering Information Non-Listed Parts

.

Introduction

..........................

.........................

...............

...................

.........................

.............

..........

............

...............

..................

......

....................

....

..............

Follower

Bias Adjustrncnt

......

........

...................

................

......................

...............

......

....................

...............

..................

.............

......................

of

Factory Selcctcd

.......................

..............

....................

.........................

..................

......................

.........................

5-1

5-1 5-1 5-1

5-1

5-2

5-3 53

53 53

5-3

5-5 5-5

5-5

54

56

54

5-7

54

5-8

54

5-0

6-1

7-1

Number

1.1

.

Specifications

3.1 . Voltage and Current in Resistance Measurements

5.1

.

Test Equipment Required

5.2

.

Millianimeter Accuracy Check

~

..

.............................

............................

....................

................

LIST

OF

TABLES

Page Number

5.3

1.0

54

3-2

54

5-2

5.5

6-1

.

Input Resistance Chccks

.

Power Supply Voltages

.

Tubc Replacement

.

Rcplaccablc Parts

..........................

Pagc

.....................

.........................

:54

541

iii

5-3

6-2

n

List

of

Illustrations

Model

4

12A

n

.1

t,p’

Number

1-1.

Model

412A

DC

Vacuum Tube

Voltmeter

4-1.

Block Diagram

5-1.

Input Resistance Check

5-2.

AC

Rejection Check

53.

Location

54.

Input Circuit Board

5-5.

Modulator Waveform

54.

Demodulator Assembly

5-7.

input Cable Connections.

5-8.

Simplified Schematic, Voltmeter

Switching

5-9.

Simplified Schematic, Ammeter

Switching

.

. . . .

. . . . . . .

of

Adjustments

. . . .

. . .

. . * .

.

. .

.

. .

.

. . . . . .

.

. . . .

.

. . . . . .

. . .

.

. . . .

.

. .

.

. . .

.

...........

.

. .

.

...........

. . . . .

...........

.

...........

. . . . .

. .

.

...........

. . .

. . . . .

...........

. . . .

...........

.

. . .

.

...........

.

. .

.....e.....

,

. .

.

LIST

’

OF

ILLUSTRATIONS

Page Number

5-1O.Simplified Schematic, Ohmmeter

,

.

,

1-1

,

.

,

.

..

.

...

.

..

...

.

.5-10

.

.5-11

4-1

5-2

53

54

56

5-7

s-8

59

6-1.

6-2.

6-3.

7-1.

7-2.

7-3.

74.

7-5

.

. . .

.

Switching

Location

Cabinet Model

Location

Rack Model Voltage Location of Chassis Mounted.Parts,

Cabinet Model Location

Rack Model Location Schematic Diagram

Power

of

Probe

of

Supply Backdating

. . . . . .

Mechanical Parts,

.

. . . . . . . .

Mechanical Parts,

.

. . .

. . . . . . .

Assembly

. . . .

Chassis Mounted

. . .

Switch

. . .

.

. . . .

.

. . . .

. . .

. . . . . .

.

. . . . . . .

. . . .

Components

.

. . .

.

Parts,

.

. . . . . . .

.

. .

. . .

.

. .

..........

.

..........

.

..........

e.........

..........

.

..........

Page

.

.5-I

. .

6-5

.

6.6

. . 6-7 .

.

7-2

. .

7-3

..

74

.

7-5

.

7-7

2

8

b

'5

Section

VOLTMETER

9

b

AMMETER

I

Table

1-1.

Voltage Range: Positive and negative voltages from

millivolt

ranges

Accuracy

Input Resistance:

and

30

100

200

AC Rejection: A voltage at power line

line frequency reading

1500

fuull

scale to

:

+

1

%

of full scale on any range

10

mV ranges

megohms

21%

megohmsf.l% megohms

less

t

40

than

1

volts.

1000

volts full scale in

megohms

on

30

on

100

%

on

300

dB

greater

1%.

Peak voltage must not exceed

1%

on 1 mV, 3 mV,

mV range

mV range mV range and above

or

twice power

than full scale affects

Specifications

1

13

AMPLIFIER

Voltages and Currents:

Open Circuit Short Circuit

Range

XI

XI0

XI00

XlOOo

XlOK

XlOOK

XIM

XlOM

Xl00M

Voltage Cain:

AC

Rejection: 3 dB at

Volts

10

mV

100

mV IV 1v 1

1v

1v 1v

1v

1000

maximum

1

Hz,

80

Current

100~

.Olp

dB at

Model

10

mA

10

mA

10

mA

lop

'P

.lp

50

A

A A

and

4

60

12A

Hz

d

Current Range: Positive and negative currents from

1

microampere full scale to 1 ampere full scale in thirteen ranges

Accuracy

v

tnput Resistance

Range Resistance* Voltage

:

2

2% of full scale on any range

:

tnternal Shunt Full

Scale

Drop

Output: Proportional

full scale; maximum current, corresponds to

Output Impedance:

Less

Noise:

than 5 mV

Drift: negligible

to

meter indication; 1 volt at

1

.O

on upper scale.)

Less

than 2 ohms at dc

RMS

on

1

mA.

any range

(Full

scale

GENERAL

.001

mA

.003

mA

.01

mA

.03

mA

.I

mA

.3

mA

1

mA

3

mA

10

mA

30

mA

100

mA

300

mA

1000

mA

*For

total insertion resistance add

25

rcsistance at

C

I000

3

I6

100

3

I

.6

IO

3.16

.3

ohms

ohms ohms ohms ohms ohms

1

16

.1

.I

ohm ohm ohm olim olim

ohin

ohm

0.07

1

mV

0.9486

1

mV mV mV

1 mV

0.9486

10

30

100

mV

1

mV

1

mV

3

mV

ohms copper lead

Isolation Resistance: At least

by 0.1~

F

between common terminal and case

100

megohms shunted

(power line) ground

Common Mode Rejection: May be operated up to

500

Vdc

or

130

Vac from ground

f10%,

5040

Hz,

35

11-1/2

W

in. high,

7-1/2

Power: 115/230 V Dimensions: Cabinet Mount:

in. wide,

10

in. deep

Rack Mount:

OHMMETER

Hesistaticc Ibiige: Rcsistancc from

center-scale to

raiiges

decade

a

Accuracy:

f-

5%

of

IO0

niegolims center-scale in nine

reading froni

scale

'I

14

0.3

to 3 on Ohms

I

olim

001

29-5

Model

4 12A

Section

I

SECTION

GENERAL

1-1.

INTRODUCTION.

1-2.

The Hewlett-Packard Model

Tube Voltmeter is

a

multifunction instrument which measures the entire range resistance normally encountered in electronic equipment.

1-3.

The Model mV full scale to arranged in a

of

full scale. The input circuit

from

power line ground.

14.

The Model current from accuracy

3,

1-5.

412AIAR

of

10

sequence.

Resistance measurement capability

is

2%

from

412AIAR

IO00

V full scale in thirteen ranges

1,3,

10

sequence. Voltmeter accuracy is

412AlAR

1.OpA

of

full scale. Current ranges are also in a

1.0

measures positive

full scale

ohm center scale

412A/AR

of

dc voltages, current, and

DC

Vacuum

measures dc voltage from

is

isolated from the case and

or

negative dc

to

1.0

A

full scale with an

of

the Model

to

I00

megohms

1.0

1%

1,

I

INFORMATION

center scale in nine decade rangcs. Resistaiicc nieasureiiieiit

is

5%

accuracy

16.

The Model

between

voltage proportional to the input. Ainplificr giiiil is froiii

-1000

to

t1000,

depending on range selected.

1-7.

SPEC1

FlCATlO NS.

1-8.

Complete specifications

are listed in Table

1-9.

INSTRUMENT AND MANUAL IDENTIFICATION.

1-10.

Hewlett-Packard uses a twoscctioii cigltbdigit scrial number number

(OOO-00000).

of

your instrumcnt do not agrcc witti thosc

title page of this manual, changc sliects supplicd

will

manual

explain the diffcrenccs bctwccii instrument and the Model manual.

'

.3

and

3

412AIAR

1-1.

If

has a dc aiiiylifier output

for

the first tlircc digits

412AIAll

on

the resistance scale.

the dip- Modcl41

of

dcscribcd

2AIAR

tlic

scrial

on

tlic

with

tlic

your

in

lliis

412A-A-30188

Figure

00

1

295

1.1.

Model

412A

DC

Vacuum Tube Voltmctcr

0

Model 4 12A

h

Section

I1

2-1.

INTRODUCTION.

2-2. Tliis section contains instructions necessary for installation

the Model 412AIAR

DC

Vacuum Tube

of

Voltmeter. Included are initial inspection procedures,

cy

power and grounding requirements, installation information, and instructions for repackaging for shipment.

2-3.

INITIAL INSPECTION.

2-4.

This

instrument was carefully inspected both

and

mechanically

of

free

mars or scratches, and in perfect electrical order

upon receipt. inspected for physical damage clcctrical procedure outlined in Paragraph

electrically before shipment. It should be

To

confirm this, the instrument should be

in

transit.

performance

of

tlic instrument, using the

5-5.

If

there is damage or

Also

deficiency, see tlic warranty on the inside front cover of this manual.

2.5.

POWER

2-6.

P

Y

The Model 412AIAR can be operated from any source slide switch Power dissipation is approximately

REQUIREMENTS.

of

115

or

230

on

the rear panel selects the desired voltage.

volts at

50

or

35

60

Hz.

watts.

The

SECTION

IN

STACLATIO

test the

115/230

V

II

N

2-1

0.

INSTA 1 LATlO N.

2-1

I.

The Model 412A is intended

instrument, having a top-mounted handle and rubbcr fcct.

2-12. The Model 412AR is intended for rack mounting. Front panel height

2-13.

REPACKAGING

2-14.

The following paragraphs contain a general guidc for repackaging the original container is

is

5-7/32 inches.

FOR

SHIPMENT.

of

tlie instrument. Rcfcr to Paragraph

to

be

uscd;

have any questions, contact your Service Office. (SCC Appendix

B

NOTE

If

the instrumcnt is to be sliippcd

I

Icwlctt-i’ackard for scrvicc attach a tag to tlic instrumcnt idcntifying the owncr and indicating tlic scrvicc repair

to

be accomplislicd. lncludc tlic

model number

of

tltc instrumcnt. corrcspondcnce, identify tlic instrumcnt by modcl numbcr, scrial numbcr prcfix, and scrial numbcr.

for

use

as

a

2-16

if

it

is

not.

local

-lip-

Salcs

for office locatiwis.)

to

or

repair.

or

In

any

bcncli

2-15

If

you

and

if

G

R

0

U

N

D

I

NG

2-7.

2-8.

To protect operating personnel, the National

REQUl

Electrical Manufacturer’s Association that tltc instrument panel and cabinet

R

EMENTS.

(NEMA)

recommends

be

grounded. This instrument is equipped with a threeconductor power cable wluch, when plugged into an appropriate receptacle.

on

grounds the instrument. The offset pin

the connector is

tlie ground wire.

2-9.

To

preserve the protection feature when operating the

instrument from a twocontact outlet, use a threeprong

4b

two-prong adapter and connect the green pigtail adapter to ground.

NOTE

Operating the Model 412A/AR without grounding the third (power line ground) wire

of

the power cable will result

of

the meter and oscillation

1

29-5

zero offset the pointer.

4

J

00

in

of

2-15. Place the instrumcnt suitable packing material and metal bands.

be

purchased from your ncarcst

If

original containcr

in

original conhincr with

scat

wcll

with strong tapc

is

not aviilablc, onc

hp

Salcs

and

or

CBR

Scrvicc

Office.

2-16.lf original container

is

not to hc uscd, procccd

as

follows:

a. Wrap instrument

in

hcavy

papcr or plastic hcfurc

placing in an inncr containcr.

to

on

the

b.

Place packing material around a11

instrumcnt and protcct panel facc

strips

.

with

c. Place instrument and inncr containcr

carton tapc

or

wooden box and scal wcll with strong

or

metal hands.

sidcs

of

cardhturd

in

a hcavy

a

d. Mark shipping containcr

INSTIWMENT,”

“FRAGILE,” ctc.

“DI~LICATE

2-1

hlodcl4

12A

Section

111

SECTION

0

PER

AT1

N

G

3-1.

INTRODUCTION.

3-2.

The

-lip-

Model 412A/AR

Voltmeter nieasures dc voltages from

full

lo00 V

Current measurement ranges are from

1000

to The Model

1.0

ohm center

Resistance measurenicnt accuracy is

.3

and

provided.

+1000,

1

.O

V

at full scale. and maxinium current load is

3-3.

LOW-LEVEL ELECTRICAL PHENOMENA.

34.

Stray low-level electrical phenomena may cause error

in

low voltage measurements. When using the lower voltages

of the Model 412A, consider the possibility voltages produced by thermoelectric effects, residual charges on capacitors, battery action, cables,

scale with

mA

full

scale, with accuracy

41

2A/AR makcs resistaricc measurements from

3

on

the ohms scale. A dc amplifier output is also

Voltage

depending

an

accuracy of

scale

to

100

gain of tlic amplificr is from

on

range selcctcd. Amplifier output is

DC

Vacuum Tube

1.0

mV full scale to

1%

of

full

scale.

0.001

mA

full

scale

of

2%

of

full scale.

megohms center scale.

5%

of

reading between

-1000

to

1

.O

mA.

of

low-level

or

flexing

of

coaxial

IN

STRU

3-7.

3-8.

111

CTiO

TURN-ON PROCEDURE.

a. Make sure the proper fuse is installed for operation

with the power line voltage to be used. A slow-blow fuse should be used for operation, and a operation.

b. Connect

Allow

VOLTAGE

NS

BEFORE CONNECTING PRIMARY POWER, MAKE SURE THE REAR PANEL 115/230 V SLIDE SWITCH

IS

SET

TO

THE POWER LlNE VOLTAGE INCORRECT SETTING MAY

RESULT IN DAMAGE TO THE INSTRUMENT.

to

ac power and turn instrument ON.

a

S-minute warm-up period.

MEASUREMENT.

TO

BE

0.4

A slow-blow fuse for

USED.

0.6

I

IS

230

A

V

3-5.

The voltagc probe, currentlresistance lead, and common lead have a very low thermoelectric effect with copper, the most commonly used conductor. However, some component leads such as transistors and reed relays may have leads

of

made thermoelectric voltage when joined with copper. Whenever possiblc, connect tlic possible, the voltage probe and common lead should both

In:

conncctcd

and both connection points maintained at the same

tc

111

pcra

34.

To minimize tlic possibility making probe tip and common lcad alligator clip are clean.

surc

tlic component leads or other points of connection are clean. The prcsence niay cause noticeable nieasiirement error due to battery action.

of

the Model 412A/AR are all designed to

such alloys as nickel-iron, which produce a

412A

leads to copper. If this

to

the

smic

kind

of

inctal compncnt lead,

t

urc.

of

battery action when

low

voltage mcasurcments, make sure the 412A

Also

of

sonic chemicals such

NOTE

Operating the Model 412A/AR without grounding the third (power line ground)

of

wire zero offset the pointer.

the power cable will result in a

of

the meter and oscillation

as

solder flux

of

is

not

be

a.

Set

FUNCTION switch to VOLTS, and select

proper polarity.

b. Set RANGE switch to desired range.

set

switch to high range and downrange as

necessary.

c.

Connect VOLTS and component, and read voltage.

DO

NOT OVEKLOAD THE INSTRUMENT. MOMENTARY OVERLOADS UP TO TEN TIMES FULL SCALE WILL NOT DAMAGE THE INSTRUMENT; HOWEVER,

CURRENT SHUNTS, AND

INTERNAL RESISTANCE

STANDARDS ARE NOT PROTECTED FROM EXTREME OVERLOAD.

33.

CURRENT MEASUREMENT.

a. Set FUNCTION switch to

b.

Set RANGE switch to desired range. select high range and downrange as necessary.

COM

If

in doubt,

leads across circuit

MA.

If

in doubt,

or

00

1

29-5

3-1

section

.

3-10.

111

c. Deenergize circuit

d. Connect

COM leads.

e.

Energize circuit,

up-scale indication, and read current.

When making current measurements,

make

the circuit common

ground (&)terminals on rear panel.

RESISTANCE

a.

Set

FUNCTION switch

b.

If resistance make sure

c.

Connect measured, using

to

412A

into circuit,

NOTE

sure

there

is

no connection between

MEASUREMENT.

to

be

power

is

412A

across circuit

MA/OHMS

be

measured.

set

POLARITY

6)

and power line

to

OHMS.

measured

turned

off.

and COM leads.

using

MA/OHMS

switch

is

part of a circuit,

or

component

to

and

for

be

Model

41

2A

d.

Set

RANGE switch

near center scale as possible, and read resistance on

OHMS

scale.

3-1

1.

When measuring the resistance such as transistors and diodes, it is often desirable what voltage and current were present in obtaining the resistance measurement. Table voltage and shortcircuit current available at during resistance measurements. Voltage and current are read on the top scale The meter reading is directly proportional across the device being measured, and inversely proportional device being measured on the

.25

on

the

top

100

mV (Table across the device. To determine the current, subtract the meter reading multiply by the shortcircuit current listed in Table Since the current shown indicates measured. The resistance measurement, then, indicates an equivalent resistance

20

mV, and a current

of

to

the resistance scale. The meter

scale. Since full-scale voltage for the

a

current

of

the current.

34),

of

.2

from the full scale reading

of

so

that meter indication is as

of

non-linear devices

3-1

lists the open-circuit

the

412A

the meter

this indicates a voltage

for

all

resistance ranges.

to

the voltage

As

an example, assume that

XI0

range gives a reading

also

indicates

XI0

of

for

the

XI0

range

is

10

8

mA through the device being

2.5

ohms, with an applied voltage

of

8

mA.

to

know

leads

.2

range is

20

mV

1,

and

3-1

mA,

this

a

of

on

.

Resistance Range

XI

XI0

XI00

X1

K

XlOK

XlOOK

XIM

XlOM

XlOOM

Table

3-1.

Voltage and Current in Resistance Measurements

1

OpenCircuit Volts

1

on top scale)

(at

10

mV

100

mV

IV

1v

IV

1v

ShortCircuit Current

0

on tot, scale)

(at

10

mA

10

mA

10

mA

1

mA

l00pA

IO

pA

lPA

0.1

pA

0.01

pA

3-2

00

1

29-5

Model

4

12A

Section

111

3-12.

AMPLIFIER OPERATION.

3-13.

The Model used to drive devices permanent record

4

412A/AR

such

of

measurements. Output level is

DC

Amplifier Output may be resistance) may cause errors in meter indication and

as an analog recorder to provide a amplifier

1

.O

volt range

at full scale; maximum rated load current is currents

to

in

excess

of

1.0

gain.

Amplifier gain is from

-1000

on the

loo0

mA (less than

+lo00

range.

1000

1

.O

mA.

ohms load

on the

Load

,001

Y

00 1 29-5

I‘

3-3

Model

41 2A

Section

1V

SECTION

THEORY

4-1.

GENERAL.

4-2.

The kp- Model

amplifier circuit to produce a meter indication proportional

to the voltage, current, or resistance being measured.

4-3.

BLOCK

44.

Figure The following paragraphs describe operation of the various circuits.

4.5.

RANGE AND FUNCTION SELECTION.

4-6.

The Voltage Divider. Current Shunts, and Resistance Standards circuits provide a input in all ranges and functions. Full scale reading Simplified schematics

and

functions are shown in Figures

47.

FILTERS.

4-8.

input filtering is provided to attenuate any ac components present in the input signal. The second fdter section filters the Demodulator output.

DIAGRAM ANALYSIS.

4-1

of

1

on

412AIAR

is

a block diagram

the top scale of the meter for all ranges.

of

the switching circuits

uses a chopper-stabilized

of

the Model

0.9

mV output for full-scale

5-8

through

412AIAR.

is

defined as a

for

all ranges

5-10,

OF

IV

OPERATION

4-9.

MODULATOR, AMPLIFIER, DEMODULATOR,

AN0

CHOPPER.

4-10. A

sets the Modulator/Demodulator frequency at line frequency. The Modulator output is an ac signal proportional stabilized at output synchronized with the Modulator signal Cathode Follower. This voltage is the same polarity as the input signal.

4-11.

SELECTION.

4-12.The Cathode Follower drives the Meter and the Amplifier Output. Polarity selection provides upscale meter reading for either polarity input. The Polarity switch is disabled in the

light-beam chopper driven by a synchronous motor

516

power

to

the Model

1

,111

of

1

.O

volt for a full-scale input. The Demodulator

is

converted to a steady dc, which

CATHODE FOLLOWER AND POLARITY

412A

input. The amplifier

by the feedback network, resulting in an

so

that the amplified ac

is

applied

gain

to

the

is

DC

OHMS

function.

is

RANOC

SELtCllOW

00

129-5

r

Figure

I

4-1.

Block Diagram

4-1

6

Section V

INSTRUMENT

DC

Voltage Standard

Variable Line Transformer

DC

Voltmeter

AC

Voltmeter

~ ~ ~~

Oscilloscope

TYPE

Table

5-1.

Test Equipment Required

REQUIRED CHARACTERISTICS

Range: Accuracy:

Current Rating:

Output Voltage:

Range: Resolution Input Resistance:

Range: to

Sensitivity:

(or

253 Vac)

0-300V

0.1%

1

V

to

300

:

10

mV

300

V

10

Ma

0.01

10

to

127

V

100

Vlcm

mA

Vac

Ma

hp- 738BR Voltmeter

Calibrator

1

Superior Electric

Powerstat 3PF116

(for

1

15

V line) 3PF216

V

(for 230

hp- 427A Voltmeter

hp-

427A Voltmeter

hp- 427A Voltmeter

hp

120B

line)

Oscilloscope

Model 412A

Precision Resistors

Oscillator

Resistance:

1

10

100

1K

10

30K

100K

300

K

1M

10

100

10

-~

~

Frequency : 60 Hz

Output:

K

M

5W

1W 1/2

W

IO

V peak

Accuracy

i

1.0%

2

1.0%

f

1.0%

f

1.0%

+,

1.0%

?

0.1%

2

0.1%

2

0.1%

2

0.1%

2

1.0%

2

1.0%

k

0.1%

:

Part Number:

-hP-

hP-

-hp-

-hP- 07574442 Daven Dale

Dale MFS-112

-hP

-hP-

-hp-

200CD Wide Range

Oscillator

08

1

I-OoFiO

07574346

0757.040

07574280

1

DAS-5

MF-I

06984 16 0698-5049

0733401

08

1

1-2475

1

7

HP 412A, 412AR Operating And Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual