Fluke 187 user manual Measuring Current, Input Ranges

Model 187 & 189

Users Manual

Measuring Current

WWarning

Never attempt an in-circuit current measurement where the open-circuit potential to earth is greater than 1000 V. You may damage the meter or be injured if the fuse blows during such a measurement.

To measure ac or dc current, proceed as follows:

1.Turn off power to the circuit. Discharge all high- voltage capacitors.

2.Insert the black lead into the COM terminal. Insert the red lead in an input appropriate for the measurement range as shown in Table 3-1.

Note

Caution

To avoid possible damage to the meter or to the equipment under test, check the meter’s fuses before measuring current. Use the proper terminals, function, and range for your measurement. Never place the probes across

To avoid blowing the meter’s 440 mA fuse, use the mA/∝ A terminal only if you are sure the current is less than 400 mA.

Table 3-1. Current Measurement

(in parallel with) any circuit or component when the leads are plugged into the current terminals.

Current is the flow of electrons through a conductor. To measure current, you must open the circuit under test, then place the meter in series with the circuit.

Rotary Switch

Ior K

=or x

Input

!

#

#

Ranges

5.0000 A

10.000 A (reading flashes at

10 A, overloads (0L) at 20 A)

50.000 mA

500.00mA

500.00∝ A

5000.0 ∝ A

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