Keithley Instruments 197 Data Sheet

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DIGITAL MULTIMETERS

197A 51⁄2-Digit Multimeter

• 1µV, 1mΩ, 1nA sensitivity

•TRMS AC measurements to 100kHz

•100-point data logger, relative ref­erence, dB

•IEEE-488 and analog output option

•Backlit display

•Battery option

ACCESSORIES AVAILABLE

TEST LEADS

1681 Clip-On Test Lead Set
1751 Safety Test Leads
1754 Safety Univ. Test Lead Kit
5806 Kelvin Clip Leads

CABLES

7007-1 Shielded IEEE-488 Cable, 1m (3.3 ft)
7007-2 Shielded IEEE-488 Cable, 2m (6.6 ft)
7008-3 IEEE-488 Digital Cable, 0.9m (3 ft)
7008-6 IEEE-488 Digital Cable, 1.8m (6 ft)

PROBES/SHUNT

1600A High Voltage Probe
1651 50A Current Shunt
1682A RF Probe
1685 Clamp-On Current Probe

OUTPUTS

1972A IEEE-488 Interface with Analog

Output

1973A IEEE-488 Interface

POWER

1978 Rechargeable Battery Pack

RACK MOUNT KITS

1010 Single Fixed Rack Mount Kit
1017 Dual Fixed Rack Mount Kit

OTHER

1979 Spare Parts Kit

See page 235 for descriptions of all accessories.

The Model 197A combines 51⁄2-digit resolution (on a 220,000-count display) with 1µV, 1nA, 1mΩ sen-
sitivity. Basic DCV accuracy is 0.011%.

Extended Performance

Measure voltage over nine decades from 1µV to 1000V.
Input resistance on the two lowest voltage ranges exceeds
1GΩ. TRMS AC measurements can be made to 100kHz.
Make 2- or 4-terminal ohms measurements over 11 dec­ades from 1mΩ to 220MΩ. Six current ranges measure
from 1nA to 10A.

The microprocessor-based 197A is loaded with smart fea­tures. Display annunciators indicate the measurement
mode and units. Autoranging on V, Ω, and dB automatic­ally displays maximum resolution.

dB Ranges

Audio and communication circuit analysis is easy with
direct-reading dB measurements referenced to 50, 75, 93,
135, 300, or 600 ohms. Resolution is 0.01dB above 1mV.

Pushbutton relative reference (REL) nulls out or zeros on­range readings. REL can also null out circuit voltage offsets
or lead resistances and create a new baseline for differential measurements. REL works with the dB
function to establish the 0dB point or to make convenient amplifier stage gain comparisons.

The DATA LOGGER stores up to 100 readings at six automatic rates from three per second to one per
hour, or manually at the touch of a button. Minimum and maximum readings are continuously
updated (3 per second) in the DATA LOGGER mode.

ORDERING INFORMATION

All include Instruction Manual and Model
1751 Safety Test Leads.

197A Autoranging Microvolt DMM
197A/1972A Autoranging DMM with

IEEE-488 Interface and
Analog Output

197A/1973A Autoranging DMM with

IEEE-488 Interface

197A/1978 Autoranging DMM with

Rechargeable Battery Pack

197A/72A/78 Autoranging DMM with

IEEE-488 Interface, Analog
Output and Rechargeable
Battery Pack

197A/73A/78 Autoranging DMM with

IEEE-488 Interface and
Rechargeable Battery Pack

This product is available with an Extended
Warranty. See page 635 for complete order­ing information.

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QUESTIONS?

1-800-552-1115 (U.S. only)

Call toll free for technical assistance,

product support or ordering information, or

visit our website at www.keithley.com.

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Digital Calibration

Calibration factors for each range are stored in a non-volatile RAM. Without potentiometers to
adjust, repeatable calibration is fast and easy.

Powerful Options

Combine IEEE-488 interface with real-time analog monitoring with the 1972A Analog/IEEE Output
option. The TALK/LISTEN interface has range programmability on volts and ohms. The smart fea­tures, dB, REL, digital calibration, and DATA LOGGER are available over the bus. The analog output
has selectable gain of ×1 or ×1000. The REL feature zeros the analog output as well as the display. The
IEEE-488 interface alone is also available as the 1973A option.

The 1978 battery pack option enables data to be collected in the field with the DATA LOG­GER and processed back in the lab by transferring the data to an IEEE-compatible printer.

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DIGITAL MULTIMETERS

197A 51⁄2-Digit Multimeter

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DC VOLTS

RANGE RESOLUTION RESISTANCE 22°–24°C 18°–28°C

200mV 1 µV >1 GΩ 0.007 + 2 0.016 + 3

20 V 100 µV 11 MΩ 0.006 + 2 0.015 + 3

200 V 1 mV 10 MΩ 0.006 + 2 0.015 + 2

1000 V 10 mV 10 MΩ 0.007 + 2 0.015 + 2

*Relative to calibration accuracy. **When properly zeroed.

NMRR: >60dB at 50Hz, 60Hz ±0.1%.
MAXIMUM ALLOWABLE INPUT: 1000V DC or peak AC (<10 seconds per

minute on 200mV and 2V ranges; 300V rms continuous).

SETTLING TIME: 1 second to within 3 counts of final reading on range.
dB MODE (ref: 600Ω): Accuracy: ±(0.02dB+1 count) above –78dBm.

Resolution: 0.01dB above 5% of range.

DC AMPS MAXIMUM ACCURACY (1 Year)

RANGE RESOLUTION BURDEN ±(%rdg + counts)

200 µA 1 nA 0.3 V 0.1 + 15

200mA 1 µA 0.3 V 0.2 + 15

2000mA 10 µA 0.8 V 0.2 + 15

*Above 5A derate 0.15% rdg per amp for self–heating.

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OVERLOAD PROTECTION: mA Input: 2A fuse (250V ), externally acces-

sible. 10A Input: 20A for 15s, unfused.

SETTLING TIME: 1 second to within 3 counts of final reading.

ANALOG/IEEE OUTPUT (Model 1972A Option)

ANALOG OUTPUT:

Accuracy: ±(0.25% of displayed reading + 2mV).
Response Time: Follows display conversion rate.
Level: 1V=100,000 counts on ×1 gain. 1V=100 counts on ×1000 gain.

Maximum output voltage = 4V.

Output Resistance: 1000Ω.
Isolation: 500V peak, Input LO to Output LO.

IEEE OUTPUT: See IEEE BUS IMPLEMENTATION.

MULTILINE COMMANDS: DCL, SDC, GET, GTL, UNT, UNL, SPE, SPD.
UNILINE COMMANDS: IFC, REN, EOI, SRQ, ATN.
INTERFACE FUNCTIONS: SH1, AH1, T5, TE0, L4, LE0, SR1, RL0, PP0,

DC1, DT1, C0, E1.
PROGRAMMABLE PARAMETERS: Range (DCV, ACV, Ω only), REL, dB,

EOI, Trigger, Calibration, SRQ, Status, Output Format, Terminator,
Data Logger Retrieval.

ACCURACY**
±(%rdg + counts)

INPUT 24 Hr.,* 1 Year,

2 V 10 µV >1 GΩ 0.005 + 2 0.011 + 2

VOLTAGE 18°–28°C

2mA 10 nA 0.3 V 0.1 + 15

20mA 100 nA 0.3 V 0.1 + 15

10 A 100 µA 0.3 V 0.5 + 15*

30V peak, Output LO to earth ground.

IEEE BUS IMPLEMENTATION

(1972A ANALOG/IEEE & 1973A IEEE OPTIONS)

TRMS AC VOLTS

RANGE 20Hz–50Hz 50Hz–10kHz 10kHz–20kHz 20kHz–50kHz 50kHz–100kHz

200 mV 1.00 + 100 0.35 + 100 0.6 + 200 1.5 + 250 5 + 400

2V–200V 1.00 + 100 0.35 + 100 0.6 + 200 1.5 + 250 3 + 400

750 V 1.25 + 100 0.75 + 100 1.0 + 200 1.8 + 250 3 + 400

ACCURACY (1 Year)*

18°–28°C ±(%rdg + counts)

dB MODE ACCURACY (±dBm)

RANGE INPUT 20Hz–10kHz 10kHz–20kHz 20kHz–50kHz 50kHz100kHz

2V–750V 200 mV to 750 V 0.18 0.18 0.28 0.50

Resolution: 0.01dBm above 0.5% of range.
*Above 1800 counts. **Above 18000 counts.

MAXIMUM ALLOWABLE INPUT: 750V rms, 1000V peak (<10 seconds per minute on 200mV and 2V

ranges; 300V rms continuous). 10

3dB BANDWIDTH: 300kHz typical.
INPUT IMPEDANCE: 1MΩ paralleled by <75pF on 200V and 750V ranges; 1.1MΩ on 200mV, 2V, and

20V ranges. Capacitively coupled.

SETTLING TIME: 1 second to within 0.1% of final reading on range.
dB REFERENCE IMPEDANCE: 50, 75, 93, 135, 300, or 600 ohms, front panel selectable.

TRMS AC AMPS

*Above 1800 counts.
**1kHz max. Above 5A derate 0.15% rdg/amp for self–heating.

SETTLING TIME: 1 second to within 0.1% of final reading.

OHMS

RANGE RESOLUTION I–SHORT UNKNOWN 22°–24°C 18°–28°C

200 Ω 1mΩ 2mA 0.5 V 0.01 + 2* 0.018 + 3*

200 kΩ 1 Ω 40µA 4.0 V 0.014 + 2 0.026 + 2

200 MΩ ** 10 kΩ 400nA 5.0 V 2.00 + 1 2.00 + 1

*When properly zeroed. **Appropriate range selected automatically in MΩ.

CONFIGURATION: Automatic 2- or 4-terminal.
MAXIMUM ALLOWABLE INPUT: 450V DC or peak AC 10 seconds per minute. 350V rms continuous.
OPEN CIRCUIT VOLTAGE: +5V.
DIODE TEST: Display reads junction voltage up to 2.2V. Test Current: 1.6mA nominal.
SETTLING TIME: 2 seconds to within 3 counts of final reading on range.

(–12 to 59.8dBm)

200 mV 20 mV to 200 mV 0.18 0.18 0.28 0.65

(–32 to –12dBm)

2 mV to 20 mV 0.85 1.10 2.00 —

(–52 to –32dBm)

1 mV to 2 mV 2.00 3.00 — —

(–58 to –52dBm)

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V·Hz maximum.

RANGE BURDEN 20Hz–50Hz 50Hz–10kHz 10kHz–30kHz

200µA–20mA 0.3 V 1.0 + 100 0.8 + 100 2 + 250

200 mA 0.3 V 1.0 + 100 0.8 + 100 –

2000 mA 0.8 V 1.0 + 100 0.8 + 100 –

10 A 0.3 V 1.5 + 100 1.0 + 100** –

2kΩ 10 mΩ 2mA 4.0 V 0.01 + 2 0.018 + 2

20 kΩ 100mΩ 400µA 4.0 V 0.014 + 2 0.026 + 2

2MΩ ** 10 Ω 4µA 4.0 V 0.02 + 2 0.035 + 2

20 MΩ ** 100 Ω 400nA 4.0 V 0.10 + 2 0.12 + 2

MAX VOLTAGE 18°–28°C ±(%rdg+counts)

OUTPUT ACCURACY

NOMINAL ACROSS 24 Hr., 1 Year,

ACCURACY (1 Year)*

MAX.V ±(%rdg+counts)

DISPLAY: Backlit ±220,000-count LCD, 0.45 in height;

polarity, function, range, and status indication. Back­lighting is switch selectable.

RANGING: Auto or manual on DC volts, AC volts, and

ohms; manual on AC amps and DC amps.

AUTORANGING TIME: 300ms per range average.
RELATIVE: Pushbutton allows zeroing of on range read-

ings. Allows readings to be made with respect to base­line value. Front panel annunciator indicates REL
mode.

DATA LOGGER and MIN/MAX: 100 reading storage capaci-

ty; records data at one of six selectable rates from 3 read­ings/second to 1 reading/hour or by manual triggering.

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GENERAL

Also detects and stores maximum and minimum read­ings continuously while in data logger mode.

CONVERSION RATE: 3 readings/second.
OVERRANGE INDICATION:“OL” displayed.
CREST FACTOR (ratio of peak value to rms value), AC

FUNCTIONS: 3.

MAXIMUM COMMON MODE VOLTAGE: 500V peak.
COMMON MODE REJECTION RATIO (1kΩunbalance):

>120dB at DC, 50Hz, 60Hz ±0.1%. >60dB in AC volts.

TEMPERATURE COEFFICIENT (0°–18°C & 28°–50°C):

±(0.1 × applicable one year accuracy specification)/ °C.

ENVIRONMENT: Operating: 0°–50°C; <80% relative

humidity up to 35°C; linearly derate 3% RH/°C,
35°–50°C. Storage: –40° to +70°C.

WARM–UP: 1 hour to rated accuracy.
POWER: 105–125V or 210–250V (external switch sel-

ected), 90–110V available; 50–60Hz, 12VA. Removable
power cord. Optional 5–7 hour battery pack, Model

1978.

DIMENSIONS, WEIGHT: 89mm high × 235mm wide ×

275mm deep (3

1.8kg (3 lb, 14 oz).

ACCESSORIES SUPPLIED: Model 1751 Safety Test

Leads, instruction manual.

1

⁄2in × 91⁄4in × 103⁄4 in). Net weight

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