Specifications

16
Measurement Operation(3)
Warning
Never attempt an in-circuit current measurement
where the open-circuit voltage between the circuit
and ground is greater than 60V.
If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be hurt.
Use proper terminals, function, and range for the
measurement. When the testing leads are connected
to the current terminals, do not parallel them across
any circuit.
The measurement ranges of AC current are: 200.0µA,
2.000mA, 20.00mA, 200.0mA and 10.00A.
The measurement ranges of DC current are: 200.0 µA,
2.000mA, 20.00mA, 200.0mA and 10.00A.
To measure current, do the following:
1. Turn off power to the circuit. Discharge all high-
voltage capacitors.
2. Insert the red test lead into the µAmA or 10A terminal
and the black test lead into the COM terminal.
Use the 10A terminal and 10A or 10A range if
the current value to be tested is an unknown.
3. Set the rotary switch to an appropriate measurement
position in A range or A .
4. AC current is displayed as an effective value of since
wave (mean value response).
5. Break the current path to be tested. Connect the red
test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.
6. Turn on power to the circuit.
The measured value shows on the display.
Model UT90B: OPERATING MANUAL