Zeroing Of Test Lead Resistance; Possible Sources Of Error - Megger BMM500 Series User Manual

Operation
the reading will hold for a few seconds and then
reset. This range is not suitable for diode
testing since the automatic contact detector will
not be activated when connected to a diode.
1. Set the selector switch to Ω.
2. Connect the test leads.
3. The test will activate automatically.
4. After the test probes are disconnected, the
reading will be held for a few seconds.
Fig.2
Z e roing of Test Lead Resistance
The resistance of the test leads can be nulled
on the continuity range (up to 9,99Ω). The null
information is retained in non-volatile memory
and so will be remembered when the instrument is
switched off.
1. Select the Continuity range.
2. Short the test leads across a known good
conductor using prods.
3. When the reading has stabilised, press the
TEST button. The zero offset symbol
will appear.
4. To release the zero offset press the TEST
button again.
Possible sources of erro r
Measurements and results can be effected by
the following:
• The impedance of operating circuits
connected in parallel
• Impedance such as inductors that vary during
the measurement
• Apoor connection to the circuit under test.
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