Thurlby Thandar Instruments 1705 User Manual

Model 1705

Programmable True RMS Multimeter

INSTRUCTION MANUAL

Table of Contents

Introduction 2 Specifications 3 Safety 8 EMC 9 Installation 10 General Operation 12 Making Basic Measurements 16 Dual Measurement Mode 19 Advanced Features 21 Data Logging and Printing 25 Calibration 27 Maintenance 28 Remote Operation 29 Remote Commands 34

General Commands 34 Main Display Commands 35 Dual Measurement Mode Commands 37 First Level Modifier Commands 37 Second Level Modifier Commands 38 Data Logging Commands 40 Calibration Commands 40

Default Settings 41

Introduction

This programmable true RMS multimeter has dual meas ur em ent capability and a dual display † which can show either two independent measurements, a measurement together with its range or a measurement with one of the many calculated functions available.

The key features are:

• Large, high contrast, liq uid cr ystal dual display.

• 0.04% basic accuracy, 12000 counts.

• Manual or autoranging.

• DC and AC Volts, DC and AC current, Resistance, Capacitance, and Frequency

measurement; Continuity and Diode checks.

• True RMS AC and AC+DC measurement.

• Display nulling and Ohms null.

• Touch hold mode - holds onto a stable reading until updated.

• 100 point data logger.

• Measurement post-processing to give:

dB and power measurement with settable reference impedance percentage deviation from a user-enter ed reference linear scaling with offset limits comparison f or go/no go testing automatic storage of m inimum and m aximum r eadings.

• Remote control via addressable RS232 (standard) or GPIB (factory-fit option) interfaces.

• Closed case software calibration.

• Fully compliant with EN61010-1 Safety and EN61326 EMC standards.

† Licensed under U.S. Pat. 4,825,392

Range

Accuracy

Resolution

100mV

0.06% ± 3 dig.*

10uV

* after null

1000mV

0.04% ± 2 dig.

100uV

10V

0.06% ± 2dig.

1mV

100V

0.06% ± 2 dig.

10mV

1000V

0.06% ± 2 dig.

100mV

1MΩ ac attenuator is in parallel with the 10MΩ dc attenuator.

Maximum Input:

1kV DC or AC peak, any range.

NMR:

>60dB at 50/60Hz.

(typical):

100V ranges <-1dB at 100kHz.

Input Impedance:

1MΩ//<100pF

Maximum Input:

750V rms, 1000V peak; any range.

Range

Max AC

Range

Max AC

The table shows the maximum AC voltage

100mV, 1000mV

6V 10V

80V

(45Hz-50kHz) that can be applied without

100V

200V

1000V

affecting the accuracy of the DC measurement.

ACCURACY

Accuracies apply for 1 year 19°C to 25°C. Temperatur e c oefficient outside these limits is <0.1 x quoted range accuracy per °C.

DC Vol ts

Specifications

Input Impedance:

1kΩ Unbalanced CMR:

10MΩ//<100pF, except for Vdc plus Vac measur em ent when the

>90dB at DC/50Hz/60Hz.

Maximum Allowable AC Voltage While Measuring DC Voltage

AC Volts (True RMS)

Range Accuracy Resolution

45Hz - 10kHz 10kHz - 20kHz 20kHz - 50kHz

100mV 1% ± 20 dig. - 10µV

1000mV 1% ± 50 dig 100µV

10V 0.2% ± 20 dig 0.2% ± 20 dig 1% ± 80 dig 1mV 100V 1% ± 80 dig 10mV 750V - 100mV

Accuracy specifications apply for readings bet ween 1,000 and 12,000 c ounts. Additional error at crest factor = 3 t ypically 0.2%.

Extended frequency performance

1kΩ Unbalanced CMR:

100mV range <-1dB at 50kHz; 1000mV, 10V and

>60dB at DC/50Hz/60Hz

Range

Accuracy

Resolution

100Ω

0.1% ± 3 dig.

10mΩ

1000Ω

0.08% ± 2 dig.

100mΩ

10kΩ

0.09% ± 2 dig.

1Ω

100kΩ

0.09% ± 2 dig.

10Ω

1000kΩ

0.12% ± 2 dig.

100Ω

10MΩ

0.5% ± 2 dig.

1kΩ

20MΩ

0.5% ± 2 dig.

10kΩ

Maximum Input:

300V DC or AC rms, any range.

Maximum Open Circuit Voltage:

Range

Accuracy

Resolution

1mA

0.1% ± 3 dig.

100nA

100mA

0.1% ± 3 dig.

10uA

10A

0.3% ± 3 dig. to 1A

1mA

10A

1.0% ±3 dig. to 5A

1mA

10A

3% ± 10 dig to 10A

1mA

Maximum Input:

mA ranges - 500mA DC or AC rms, 250V, fuse protected.

10A range - 10A DC or AC rms, 250V, f us e pr ot ec t ed.

Typical Voltage Burden:

mA ranges - <250mV

10A range - <500mV

Range

Accuracy (45Hz - 10kHz)

Resolution

1mA

0.35% ± 20dig.

100nA

100mA

0.35% ± 20 dig.

10uA

10A

0.5% ± 20 dig. to 1A

1mA

10A

1.2% ± 20 dig to 5A

1mA

10A

3% ± 20 dig. to 10A

1mA

Maximum Input:

mA ranges - 500mA DC or AC rms, 250V, fuse protected.

10A range - 10A DC or AC rms, 250V, f use protected.

Typical Voltage Burden:

mA ranges - <250mV

10A range - <500mV

(AC + DC) Voltage Accuracy

Total measurement err or will not exceed the sum of the separate ac and dc accuracy specifications plus 1 display count.

Resistance

DC Current

AC Current (Tru e RMS)

Accuracy specifications apply for readings between 1,000 and 12,000 counts. Additional error at crest factory = 3 typically 0.2%.

Range

Accuracy

Resolution

100Hz

0.01Hz

1000Hz

0.01% ± 1 dig.

0.1Hz

10kHz

1Hz

100kHz

10Hz

Range:

10Hz to 100kHz

for all other Vac and Iac ranges.

Range

Accuracy

Resolution

100nF

100pF

1uF

2% ± 5 dig.

1nF

10uF

10nF

100uF

5% ± 5 dig.

100nF

Continuity:

1000Ω range selected; audible tone sounds for impedance <10Ω.

Diode Test:

Test current appr oximat ely 0.5mA; displays voltages up to 1.2V.

Voltage:

Maximum Input:

300V DC or AC rms, any range.

display 5 digits 10mm high.

Scale Length:

4¼ digits (12000 counts) in most modes.

Annunciators:

LCD annunciators for all ranges, functions and program modes.

Reading Rate:

Varies with f unct ion, m aximum 4/sec.

Overrange:

Display flashes 12000 if input too great for range.

Overflow:

Displays -Or- if calculated result overflows display.

Null (Relative)

Stores current reading and subtracts it from future readings.

Ω Null:

Additional non-volatile function for nulling test lead res istance.

Hold:

Reading is frozen

T-Hold (Touch & Hold):

Reading is frozen when stable.

impedance.

Frequency

Input sensitivity: Better than 30m Vrms (100mV range); bett er than 10% of range

Capacitance

10nF

Continuity and Diode Test

Maximum Open Circuit

DISPLAY

Display Ty pe: High contrast LCD. Main display 4½ digits 17mm high, secondary

10pF

COMPUTING FUNCTIONS

dB:

Displays measurement in dBm relative to 600Ω or other user-entered

displayed.

% Deviation:

Displays % deviation from entered reference value.

Ax+B:

Linear scaling of results, with offset.

high and low limits.

Min/Max:

Minimum and maximum reading stored.

impedance.

VA:

Calculates and displays Volts x Am ps.

1s to 9999s, manually from keyboard, or by remote contact closure.

the AC input.

not a retrofittable option. Address selectable from the front panel.

5VA max. Installation Category II.

Batteries:

6 x C cells, disposable or rechargeable.

cells.

Operating Range:

+5°C to + 40°C, 20% to 80% RH

Storage Range:

−20°C to + 60°C

Environmental:

Indoor use at altitudes up to 2000m, Pollution Degr ee 1.

Safety:

Complies with EN61010-1.

EMC:

Complies with EN61326.

Size:

260(W) x 88(H) x 235(D)m m, excl. handle and feet.

Weight:

2.0kg.

AC plus DC:

Limits: Reading displayed with HI, LO, or PASS with respect to user-defined

Power: Calculates V2/R and displays in Watts with respect to a user-defined

Data Logger: Manual or automatic storage of 100 measur em ents. Storage interval

INTERFACES

Full remote control facilities are available through the RS232 ( all models) or G PI B ( alt er nat ive mains-only version) interfaces.

RS232:

The RMS value of the ac plus dc parts of the signal is calculated and

Baud rates 2400, 9600 or 19200. Complies fully with the ARC (Addressable RS232 Chain) interface standard. Address selectable from the front panel. Operational only when the meter is powered from

GPIB (IEEE-488): The meter can be specified with an IEEE-488 interface. This is an

alternative version which operates only from AC mains; IEEE-488 is

POWER REQUIREMENTS

AC Input: 220V-240V or 110-120V AC ±10%, 50/60Hz, by internal adjustment;

Battery Life: >150 hours from alk aline cells; t ypically 70 hours fr om rechargeable

GENERAL

Performance levels achieved are detailed in the user manual.

EC Declaration of Conf ormity

We Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England

declare that the

Model 1705 True RMS Programmable Multimeter and

Model 1705GP Tr ue RMS Progr am m abl e M ultimeter wi t h G PI B

meet the intent of the EMC Directive 2004/108/EC and the Low Voltage Directive 2006/95/EC. Compliance was demonstrated by conformance to the following specifications which have been listed in the Official Journal of the European Comm unit ies.

EMC

Emissions: a) EN61326-1 (2006) Radiated, Class B

b) EN61326-1 (2006) Conduct ed, Class B c) EN61326-1 (2006) Harmonics, referring to EN61000-3-2 (2006)

Immunity: EN61326-1 (2006) Immunity Table 1, ref er r ing to:

a) EN61000-4-2 (2009) Electr ostat ic Discharge b) EN61000-4-3 (2006) Electr om agnetic Field c) EN61000-4-11 (2004) Voltage Interrupt d) EN61000-4-4 (2004) Fast Transient e) EN61000-4-5 (2006) Surge f) EN61000-4-6 (2009) Conducted RF

Safety Multimeter: EN61010-1 Installation Category I measurements to 1000V,

Installation Category II measurements to 600V, Pollution Degree 1.

Probes: IEC1010-2-031 Rated to 1000V, I nstallation Category III.

CHRIS W ILDING TECHNICAL DIRECTOR

2 January 2013

Safety

This multimeter is a Safety Class I instr um ent according to IEC classification and has been designed to meet the requirem ents of EN61010-1 (Safety Requirements f or Elect r ical Eq uipm ent for Measurement, Control and Laborator y Use). It is an Installation Category II instrument int ended for operation from a nor mal single phase supply.

WARNING! THIS INSTRUMENT MUST BE EARTHED WHEN OPERATED FROM A MAINS SUPPLY

Any interruption of the mains earth conduct or inside or outside t he inst r um ent will make the instrument dangerous. Int entional interruption is prohibited. The protective action must not be negated by the use of an extension cord without a protective conductor.

When operated from the internal batteries t he m ult imeter meets the safety requirem ents for a Safety Class II (reinforced insulat ion) product and does not require grounding for safety.

The test leads supplied with this instrument meet t he r equirements of IEC1010-2-031 and are rat ed to 1000V Cat III; use only these test leads with the met er or a s et of equivalent performance.

This instrument has been tested in accordanc e with EN61010-1 and has been supplied in a safe condition. This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to r etain the inst r um ent in a safe condition.

This instrument has been designed f or indoor use in a Pollution Degree 1 environment (no pollution, or only dry non-conductive pollution) in the temperature range 5°C to 40°C, 20% - 80% RH (non-condensing). It m ay occasionally be subjected t o t emperatures between +5° and −10°C without degradation of its safety. It has been designed for Installation Category II m easur ement use to 600VDC/ACrms. and Installation Category I measurem ent use to 1000VDC/750VACrm s . The f ull definitions of Categories I and I I c an be found in IEC664, but the following can be taken as a g uide:

Installation Category I is signal level e.g. telecommunicat ion, elect r onic equipment, with smaller transient over-voltages than Installation Category II.

Installation Category II is local domestic supply level, e.g. portable equipment and appliances. In particular, Category II does not include distribution level supplies, e.g. three phase installations which are classified as Installation Category III.

For this equipment 2500V is the maximum peak t r ans ient overvoltage that can be tolerated by any terminal with respect to earth ground without impairing s afety.

Use of this instrument in a manner not spec ified by these instructions may impair the safety protection provided. Do not operate the instrument outside its rated supply voltages or environmental range. In particular excessive moisture may impair safety.

When the instrument is connected to its supply or its inputs are connected to live voltages, terminals may be live and opening the covers or removal of parts (except those to which access can be gained by hand) is likely to expose live parts. The apparatus shall be disconnected from all voltage sources before it is opened for any adjust m ent, replacement, maintenance or repair. Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of the hazard involved.

If the instrument is clearly def ec t ive, has been subject to mechanical damage, excessive moisture or chemical corrosion the safety protec t ion m ay be impaired and the apparatus should be withdrawn from use and returned for checking and repair. Make sure that only fuses with the required rated current and of the specified type are used for r eplacem ent. The use of makeshift fuses and the short-circuiting of fuse holders is prohibited.

Do not wet the instrument when cleaning it and in particular use only a soft dry cloth to clean the display window. The following symbols are used on the instrument and in this manual:

WARNING - risk of electric shock.

CAUTION - refer to accompanying documentation; incorrect operation may damage the met er.

mains earth (ground)

direct current alternating current

This instrument has been designed to meet the requirements of the EMC Directive 2004/108/EC. Compliance was demonstrated by meeting the test limits of t he following standards:

Emissions

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use. Test limits used were:

a) Radiated: Class B b) Conducted: Class B c) Harmonics: EN61000-3-2 (2006) Class A; the instrument is Class A by product category.

Immunity

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use.

Test methods, limits and per formance achieved are shown below (requirement shown in brackets):

a) EN61000-4-2 (2009) Electrostatic Discharge : 4kV air, 4kV contact, Performance B (B).

EMC

b) EN61000-4-3 (2006) Electromagnetic Field:

c) EN61000-4-11 ( 2004) Voltage Interrupt: ½ cycle and 1 cycle, 0%: Performance A (B);

d) EN61000-4-4 (2004) Fast Tr ansient , 1kV peak (AC line), 0·5kV peak ( signal connections), Performance B (B).

e) EN61000-4-5 (2006) Surge, 0·5kV (line to line), 1kV (line to ground), Performance A (B). f) EN61000-4-6 (2009) Conducted RF, 3V, 80% AM at 1kHz (AC line only; signal

connections <3m, therefor e not tested), Perform ance A (A). According to EN61326-1 the definitions of performance criteria are:

Performance criterion A: ‘During test normal performance within the specification limits.’ Performance criterion B: ‘During t est, temporary degradation, or loss of function or

performance which is self-recovering’. Performance criterion C: ‘During t est, temporary degradation, or loss of function or

performance which requires operator int er vention or s ystem r eset occurs.’

†

Note: The 1705 is a sensitive measuring instrument and, if subjected to sufficiently large RF fields, measurements may deviate beyond the accuracy specification at cer tain frequencies up to 750MHz. However, possible deviations will be small and infrequent and are not deem ed t o be a problem in practice. In all other respects the inst r um ent will operate normally (Performance A) in fields up to 3V/m.

Cautions

†

3V/m, 80% AM at 1kHz, 80MHz – 1GHz: Performance B Performance A (A) ; 1V/ m , 2.0GHz to 2.7GHz: Performance A (A).

25 cycles, 70%: Performance A (C); 250 cycles, 0%: Perform ance C ( C).

(A) and 1.4GHz to 2GHz:

To ensure continued compliance with the EMC directive observe the following precautions: a) Only use screened cables and connectors to connect between the multimeter's

RS232/GPIB interfaces and other equipment. b) After opening the case for any reason ensure that all signal and ground connec t ions ar e

remade correctly. c) In the event of part replacement becoming necessary, only use components of an

identical type, see the Service Manual.

Brown

Mains Live

Blue

Mains Neutral

Green / Yellow

Mains Earth

Mains Operating Voltage

Check that the instrument oper ating voltage marked on the rear panel is suitable for t he local supply. Should it be necessary to change the operating voltage, proceed as follows:

1) Disconnect the instrument from all voltage sources.

2) Unclip the front bezel by gently pulling the centre of each long edg e up and forward. The case halves are held together by 4 plastic push-rivets. Use the blade of a s m all

screwdriver in the slot beside each rivet to first ease out the r ivet head and t hen fully remove the rivet body. Separate t he c ase halves. Visit www.tti-test.com for further details.

3) Chang e t he t ransformer connections f ollowing the diag r am s below:

Installation

4) Reassemble in t he r everse or der.

5) To comply with safety standard requirements the oper at ing voltage marked on the rear panel must be changed to clearly show the new voltage setting.

Mains Lead

When a three c or e m ains lead with bare ends is provided it should be connected as follows:-

WARNING! THIS INSTRUMENT MUST BE EARTHED WHEN OPERATED FROM AN AC LINE SUPPLY

Battery Operation

To fit or r eplace t he six ‘C’ cells, slide off the battery cover at the rear of the instrument and remove the battery tray. For safety reasons the battery cover can only be slid off after first removing the security screw with a screwdriver. Always refit the security screw after c hanging the batteries.

Either rechargeable or disposable cells may be used; fit int o t he battery tray observing the polarity marked in the tray. Suitable cells are as follows:

Rechargeable: 2 Amp hour, e.g. NCC200, AN220, VR2C, RSH1.8, P-180C. Disposable: Alkaline, e.g. MN1400. Zinc Carbon, e.g. R14B, R14S. If batteries are fitted it is essential that the disposable/rechar geable selector switch on the rear

panel is positioned correctly before applying external power via the AC socket.

WARNING! If disposable bat t er i es ar e f i tted and the selector is set in the rechar geabl e position, there is a risk of expl osi on if the meter is connected to an AC supply.

The Rechargeable batteries are charged at a ‘trickle’ rate of C/20; the time to fully charge from completely discharged is approximately 28 hours.

Low battery condition is indicated by showing the battery symbol in the top left-hand corner of the display; when this symbol shows, approximately 5% of battery life remains.

capability.

Name

Description

1 - Power to optional PC-02

TXD

Transmitted data from instrument

RXD

Received data to instrument

4 - No internal connection

GND

Signal ground

6 - No internal connection

RXD2

Secondary received data

TXD2

Secondary transmitted data

GND

Signal ground

This section is a general introduction to t he features and organisation of the multimeter intended to be read before using the instr ument for the first time. Detailed operation is covered in later sections, starting with Making Basic Measurements.

Connections

Input Sockets

The input sockets are 4mm safety sockets on a 19mm pitch designed to accept 4mm safety plugs with fixed or retractable shrouds. The sockets are all rat ed to 1000V (Cat I)/600V (Cat II) with respect to earth ground.

The input impedance between V/Ω and COM is nominally 10MΩ on dc ranges and 1MΩ on ac ranges. The black COM socket is considered less positive than the red s ocket.

The mA/10A current sockets are low impedance; the voltage burden between mA/10A and COM at full scale is <250mV for the m A ranges and <500mV for the 10A range. The black COM socket is considered less positive than the white mA/10A sockets.

Multimeter Test Leads

General Operation

RS232

The test leads supplied meet the requir em ents of IEC1010-2-031 and are rated to 1000V Cat II I . Use only the test leads provided, or a set of similar performance, to ensure safe oper ation. Alternative test leads should be rated to at least 1000V (Cat I ), 600V (Cat II) and 10A current

The RS232 interface only operates when the instrument is r un from an ac supply; RS232 signal ground is then connected to the safety ground. The interface is fully isolated f r om t he measurement system.

9-pin D-connector compatible with the Thurlby Thandar ARC (Addressable RS232 Chain) system. The pin connections are shows below:

Pin 2, 3 and 5 may be used as a conventional RS232 interface with XON/XOFF handshak ing . Pins 7,8 and 9 are additionally used when the instrument is connected to the ARC interface. Signal grounds are connected to saf ety ground.

To ensure compliance with EMC legislation use only screened cable assemblies with screened connectors when connecting to other equipment .

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