HP 972a User manual

HP 972A and 973A Multimeter
User’s Guide
Part Number 00972-90002
March 1995
© Copyright Hewlett-Packard Company 1994, 1995
All Rights Reserved

972A
973A

HP 972A and 973A Multimeters
Table of Contents
SafetySummary. .. .. .. .. .. .. .. 1-4
SafetySymbols . .. .. .. .. .. .. .1-4
Maximum Overvoltage Limitations...1-5
ProbesandTestLeads. .. .. .. .. 1-6
Operation. .. .. .. .. .. .. .. .. .. 1-7
Terminals, Shutter, &TestLeads...1-7
FunctionSwitch . .. .. .. .. .. .. .1-8
FunctionKeys. .. .. .. .. .. .. .. 1-9
Function Keys/Function Switch Matrix ..1-12
Display. .. .. .. .. .. .. .. .. .. 1-13
Audio . .. .. .. .. .. .. .. .. .. .1-13
CalibrationandAdjustment . .. .. .. .1-14
RequiredTestEquipment . .. .. .. .1-14
CalibrationProcedure . .. .. .. .. .1-14
Maintenance. .. .. .. .. .. .. .. .. 1-15
BatteryReplacement. .. .. .. .. .. 1-15
FuseReplacement . .. .. .. .. .. .1-15
Troubleshooting . .. .. .. .. .. .. .1-16
Cleaning . .. .. .. .. .. .. .. .. .1-16
Replaceable Parts/Accessories.....1-16
Specifications . .. .. .. .. .. .. .. .1-17
General. . . . . . . . . . . . . . . . . . . 1-17
DCVoltage. . . . . . . . . . . . . . . . . 1-17
ACVoltageHP972A. . . . . . . . . . . 1-18
ACVoltageHP973A. . . . . . . . . . . 1-18
AC+DCVoltageHP973A. . . . . . . 1-19
DCCurrent. . . . . . . . . . . . . . . . . 1-19
ACCurrent. . . . . . . . . . . . . . . . . 1-20
Resistance. . . . . . . . . . . . . . . . . 1-20
Continuity . .. .. .. .. .. .. .. .. .1-20
Diode . .. .. .. .. .. .. .. .. .. .1-20
Capacitance . .. .. .. .. .. .. .. .1-20
Frequency(Volts). . . . . . . . . . . . . 1-21
Frequency(Amps). . . . . . . . . . . . . 1-21
Temperature . .. .. .. .. .. .. .. .1-22
TemperatureHP973A . .. .. .. .. .1-22
dBmHP973A. . . . . . . . . . . . . . . 1-22
Adjustments. . . . . . . . . . . . . . . . . 6-1
CalibrationTable. . . . . . . . . . . . . . . 6-1
Replaceable Parts/Accessories ......6-4
Disassembly . .. .. .. .. .. .. .. .6-5
DeclarationofConformity
1 - 3

Safety Summary
The CAUTIONS and WARNINGS which appear on the following pages must be followed to
ensure operator safety and to retain the operating condition of the Multimeter.
1. Do not use this product beyond its specifications or for uses not intended for this product
as identified by the product functions, ranges, and hazards as indicted below.
2. To minimize possible electric shock hazard condition, connect only two leads at any one
time to any of the multimeter terminals.
3. To prevent possible electric shock hazard condition when using the current function, do
not leave one probe connected to the circuit under test and the other probe disconnected,
exposed, and readily accessible (touchable).
Safety Symbols
Indicates the operator must refer to an explanation in this manual.
Indicates terminals at which dangerous voltages may exist.
WARNING
TO AVOID ELECTRICAL SHOCK or damage to the multimeter, do not apply more than
±1000 Vdc or 1000 Vrms between any terminal and earth ground. Use caution when working
with voltages above 60 Vdc or 42 Vpeak. Ensure test leads are in good condition.
WARNING
POSSIBLE ELECTRICAL SHOCK. Do not make measurements if the case is damaged or the
rear cover is removed. Remove all electrical inputs before removing the rear cover.
WARNING
POSSIBLE ELECTRICAL SHOCK or FIRE HAZARD. Do not expose this multimeter to rain or
moisture. Do not operate the multimeter in the presence of flammable gases or fumes.
1 - 4

WARNING
POSSIBLE ELECTRICAL SHOCK. Calibration and performance tests are to be performed by
qualified personnel only. Do not attempt calibration or test procedures unless qualified to do so.
CAUTION
To avoid damage to the multimeter for inputs above 250 Vdc or Vac, disconnect the test leads
before changing functions. Do not exceed the maximum input limits shown in the following table.
Maximum Overvoltage Limitations (AC and DC Voltage Functions)
1000V
MAX indicates the maximum voltage between input terminals and earth is ±1000 V (dc or ac rms).
Do not use the multimeter on any ACV circuit where the maximum impulse overvoltage may
be more than 4000Vpk or any DCV circuit where the maximum impulse overvoltage may be
more than 2500Vpk between the COM and VOLT terminals. Excessive impulse overvoltage
can damage the multimeter voltage functions. Do not measure branch circuits (CAT II) over
600V to earth nor service panel circuits (CAT III) over 300V to earth.
Safety Summary
1 - 5

Function Maximum Operating Input
10 A ±10 A (dc or ac rms) / 600 V
mA or µA±500 mA (dc or ac rms) / 250 V
Capacitance, Diode Test,
Resistance, Continuity,
Temperature 660 Vrms (sinewave)
Frequency 660 V rms 2 Hz to 10 kHz
100 V rms 10 kHz to 200 kHz
V ±1000 Vdc or Vrms (sinewave)
Probes and Test Leads
1. Always inspect probes before use. Do not use test leads whose insulation has cuts,
cracks, or other damage that may result in reduced electric shock protection.
2. Keep insulation surface clean between the probe tip connector and the finger guards.
3. If probes other than the ones specified are to be used with the multimeter, be sure the
probes and their leads are rated for the voltage and current to which they will be subjected.
Do not exceed the voltage ratings for the multimeter.
4. Probes supplied with this multimeter are rated for use up to 1000Vrms or Vdc.
Safety Summary
1 - 6

Operation
Terminals, Shutter, & Test Leads
RED LEAD
Current Measurements
(0 A to 10 A)
Frequency (Amps) Measurements
RED LEAD
Current Measurements
(0 to 400 mA)
Frequency (Amps)
Measurements
BLACK LEAD
COMMON
ALL Measurements
RED LEAD
DC & AC Voltage,
Diode, Resistance,
Capacitance, Frequency (Volts),
Temperature, Continuity, and
dBm Measurements
SAFETY SHUTTER
Slide up to open shutters
for current measurement
inputs. Must have the
function switch in one of
the Current Measurement
positions to open shutter.
Close shutter to change
function switch to any
other measurement
function.
1 - 7

Function Switch
Switch
Position Display
10A DC Current
(10 mA to 10 A) AC Current (10 mA to 10 A) Frequency 1
(2 Hz to 10 kHz)
mA DC Current
(10 µA to 0.4 A) AC Current (10 µA to 0.4 A) Frequency 1
(2 Hz to 10 kHz)
µADC Current
(0.1 µA to 4 mA) AC Current (0.1 µA to 4 mA) Frequency 1
(2 Hz to 10 kHz)
Capacitance
(10 pF to 1000 µF)
Diode Test
(0 to 2 V) Auto Diode Test
(0 to ±2 V)
ΩResistance
( 0.1 Ωto 40 MΩ)Continuity (alarm at < 20 Ω)Temperature in °F
(-112°F to 302°F) Temperature in °C (-80°C to 150°C)
mV DC volts
(10 µV to 400 mV) AC volts (10 µV to 400 mV) dBm
(-59.9 to -5.7 dBm) Temperature in °F
(-58°F to 1292°F) Temperature in °C (-50°C to 700°C)
VDC Volts
( 1 mV to 1000 V) DC + AC Volts ( to 1000 V)
VAC volts
( to 1000 V) Frequency 1
(2 Hz to 200 kHz) dBm (-19.9 to 62.2 dBm)
1AC input value is shown in secondary display
HP 972A HP 973A
1 - 8

Function Keys
Power
Automatic power off after 30 minutes. Alarm sounds 30 seconds before power off.
Power off if input < 80 V or < 400 mA. Power save if input > 80 V or > 400 mA, last measurement
displayed, power consumption is reduced. Press any key or change any function to cancel. Defeat
by holding the key for 2 seconds while applying power.
Relative/Percent
Press Action Main Display Secondary Display
Makes the last displayed
measurement the reference Each measured value relative to the reference value (difference) Reference value
Calculates the percentage change
from the reference Each measured value as a percent change of the reference value Reference value
Cancels the Relative/% function Measured Value Range
Perform a zero adjust when using the 400 Ω range or 40 mV range and displayed value is less than 99 by
shorting the test leads and pressing this key. Perform a zero adjust on the 10 nF Capacitance range with the
leads open. Cycle power to erase the stored zero adjustment.
Operation
1 - 9

Minimum/Maximum 1
Press Action Main Display Secondary Display 2
Begin recording of
minimum and maximum values Each measured value Elapsed time
Display recorded maximum Maximum measurement Time of Maximum
Display recorded minimum Minimum measurement Time of Minimum
Display last recorded measurement Latest measurement Elapsed time
Pause recording of
minimum and maximum values 3Holds display Total elapsed time
Resume recording of
minimum and maximum values Each measured value Elapsed time
Press and hold 1 second to cancel ——
1Automatic power off and auto ranging are disabled when Min/Max is selected. Bargraph will indicate and
hold the maximum values of the bargraph.
2Time is recorded and displayed in minutes up to the maximum recording time of 1999 minutes.
Recording will stop at the maximum time.
3H annunciator is displayed when Min/Max recording
Average
Press Action Main Display Secondary Display
Makes the displayed measurement the
average of the last eight measurements Average value of last eight measurements Range
Disables the averaging of measurements Each measurement Range
Operation
1 - 10