GMC-I Messtechnik GmbH 23
8.3 Taking Measurement Cables and Extension Cables into
Account (up to 10 ) – ZERO Function (Roffset)
Measurement cable ohmic resistance can be subtracted from the
measurement results automatically. Proceed as follows:
Ð With the switch in the SETUP position and the SET menu at the
display, select the rLEAd parameter. Refer to page 11 for fur-
ther instructions.
During future low-resistance measurements for which cable resis-
tance is to be taken into account, ZERO appears at the display
and cable resistance R
Offset
is subtracted. Perform low-resistance
measurement as described above in the preceding pages.
9 Test Resistor for Insulation Measurement for
Checking the Insulation Measuring Instrument
According to section 5.3.1.2 of VDE 0105-100 (EN 50110-1), the
following applies: “These measuring instruments must be tested
before, and if applicable after use.”
The two outermost jacks on the connection panel must be con-
nected to each other internally via a 10 M test resistor to this
end.
The sum of test resistor and cable resistance (for both cables),
including test probes, amounts to 10 M ±5%. This value allows
for quick self-testing.
Ð Connect the measurement cables to the + and COM jacks.
Ð Insert the test probes into the above described jacks.
Ð Select the R
iSO/iNS
measuring function with the rotary switch,
as well as the desired test voltage, e.g. R
iSO
100V.
Ð Press the start key and view the measurement results.