Fluke FLK-179/EDA2 [12/18] Measuring ac or dc current

Models 175, 177 & 179

Users Manual

Measuring AC or DC Current

XW Warning

To avoid personal injury or damage to the Meter:

• Never attempt to make an in-circuit current

measurement when the open-circuit potential to earth

is >1000 V.

• Check the Meter's fuses before testing. (See “Testing

the Fuses”.)

• Use the proper terminals, switch position, and range

for your measurement.

• Never place the probes in parallel with a circuit or

component when the leads are plugged into the

current terminals.

Turn power OFF, break circuit, insert Meter in series, turn power

on.

CAT

RANGEHOLD

MIN MAX

AIK08F.EPS

Understanding AC Zero Input Behavior of True RMS Meters

Unlike averaging meters, which can accurately measure only pure

sinewaves, True RMS meters accurately measure distorted

waveforms. Calculating True RMS converters require a certain

level of input voltage to make a measurement. This is why AC

voltage and current ranges are specified from 5% of range to

100% of range. Non-zero digits that are displayed on a True RMS

meter when the test leads are open or are shorted are normal.

They do not affect the specified AC accuracy above 5% of range.

Unspecified input levels on the lowest ranges are:

• AC voltage: below 5% of 600 mV AC, or 30 mV AC

• AC current: below 5% of 60 mA AC, or 3 mA AC