MODEL 120 TRUE RMS MULTIMETER
3
Operating conditions:
x Operating Temperature and Humidity: 0°C - 40°C (32°F - 104°F)
Below 80% RH Non-condensing
x Storage Temperature and Humidity: -10°C - 60°C (14°F - 140°F)
Below 70% RH Non-condensing
x Installation category III
x Pollution Degree 2
x Indoor use only
x Altitude up to 2000 meters (6500 feet)
Accessories: Test Leads, Battery, Holster, Instruction Manual
Options: Temperature Converter, Type K Wire Temperature Probe, RS232 Cable,
Software
3.0 Symbol Definitions and Button Locations:
1) LCD Display 10) Function Select Dial
2) Hold Button 11)
‘
µ
A/mA’ Terminal
3) MAX/MIN Button 12) ‘Amp’ Terminal
4) Range Button 13) ‘COM’ Terminal
5) Backlight Button 14) ‘Volts, Ohms, Frequency, RPM, Capacitance,
6) Peak Hold Button Temperature, Diode Test Terminal’
7) Relative Button 15) RS232 Interface Connector
8) Voltage/Current/Frequency Button 16) Holster
9) Second Function Button 17) Tilt Stand
MODEL 120 TRUE RMS MULTIMETER
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5.7 Frequ ency and RPM Measurements
1. Connect the red test lead to the
‘Hz’
jack and the black test
lead to the ‘
COM
’ jack.
2. Set the Function Selector switch to the Hz RPM function.
For RPM measurements, press the blue button to select the
RPM function.
3. Connect the test leads in parallel with the circuit being
measured.
4. Read the Frequency or RPM on the instrument display.
5.8 Temperature Measurements
1. Plug the optional temperature converter module into the
‘TEMP’
and
‘COM’
jacks, taking care to observe the proper
polarities. Plug a Type K thermocouple into the converter,
again ensuring proper polarity.
2. Set the Function Selector switch to the °C °F function.
3. Press the blue button, if necessary, to select °C or °F.
4. Locate the thermocouple probe in the environment to be
measured and allow sufficient time for the probe
temperature to stabilize.
5. Read the Temperature on the instrument display.
5.9 Capacitance Measurements
WARNING
To avoid damage to the instrument, disconnect circuit power and discharge all
capacitors before measuring capacitance. Use the DC voltage function to
confirm that all capacitors are fully discharged.
1. Connect the red test lead to the ‘ ’ jack and the black test
lead to the
‘COM’
jack.
2. Set the Function Selector switch to the function.
3. Ensure there is no power applied to the circuit, and then
connect the test leads to the leads of the capacitor being
tested, observing proper polarity on polarized capacitors.
4. Read the Capacitance on the instrument display.
Notes: 1. The bar graph is disabled in the Capacitance measuring mode. However, in
the 4mF and 40mF ranges, the bargraph indicates the time required to
accomplish this measurement.
2. To obtain an accurate reading, the capacitor under test must be fully
discharged. This instrument will automatically discharge the capacitor, if
necessary, but requires considerable time to do so. Because of this time
factor, it is preferable to discharge the capacitor by external means. If the
instrument is discharging a capacitor prior to measurement,
disc
will appear
on the display.