Continuity / Resistance Measurement; Nulling Test Lead Resistance (Up To 9.99Ohms) - Megger MFT1700 series User Manual

4.6 Switch probe
In the V/mV/ºC mode all measurements except temperature can be made with the remote switch probe. Tests are automatic
and do not require the test button to be pressed.
.1 Connect the switch probe to the switch probe socket. The probe replaces the standard RED test lead and can now
be used as a normal test probe.
5.

Continuity / resistance measurement

IMPORTANT
The continuity test will auto-range from 0.01 Ω to 99.9 kΩ. Circuits up to 2 Ω will be tested at >200 mA. To change the test current, go
to seciton 10 - Setup.
The continuity test is automatic. The test starts as soon as the leads are connected to a circuit. The TEST button is ONLY used to null the
lead set.
Warning: Prior to any continuity testing, ensure the circuits under test are isolated and not live.
SETUP allows the follow configuration options:
Positive test current
n
Bi-Directional test current
n
Bi-directional test current allows the automatic testing of the circuit in both directions and the highest measured value being displayed
See section 10 SETUP OPTIONS.
5.1 Nulling test lead resistance (up to 9.99 ohms)
Before starting a continuity test, the test lead resistance should be nulled such that it does not add extra resistance to the
circuit being measured. Once nulled it does not need repeating for each test. Periodically it should be checked to ensure
nothing has changed.
The "Lead Null" value is retained even when the tester is switched off.
To null test leads:
.1 Short test probes or clips together and press the TEST button. The null symbol
lead null is active.
This null value is stored until the TEST button is pressed again.
.2 To cancel the LEAD NULL, separate the test leads and press the TEST button.
10
Lead null OFF
will be displayed to indicate