U1231A/U1232A/U1233A User’s Guide V
• Inspect the test leads for damaged insulation or exposed metal. 
Check the test leads for continuity. Replace damaged test leads 
before you use the meter.
• Do not operate the meter around explosive gas, vapor, or wet 
environments.
• Do not apply more than the rated voltage (as marked on the 
meter) between terminals, or between terminal and earth ground.
• If the equipment is used in a manner not specified by the 
manufacturer, the protection provided by the equipment may be 
impaired.
• Never use the meter in wet conditions or when there is water on 
the surface. If the meter is wet, ensure that the meter is dried only 
by trained personnel.
• Before use, verify the meter's operation by measuring a known 
source, for example, voltage. 
• When measuring current, turn off the circuit power before 
connecting the meter in the circuit. Remember to place the meter 
in series with the circuit.
• When servicing the meter, use only the specified replacement 
parts.
• Use caution when working above 60 V DC, 30 V AC rms, or 42.4 V 
peak. Such voltages pose a shock hazard.
• Do not use the VZ
LOW 
(low input impedance) function to measure 
voltages in circuits that could be damaged by this function’s low 
input impedance of 3 k
Ω.
• When using the probes, keep your fingers behind the finger 
guards on the probes.
• Connect the common test lead before you connect the live test 
lead. When you disconnect the leads, disconnect the live test lead 
first.