METREL MI 3290, Instruction Manual

Page: 98 / 162

MI 3290 Earth Analyser Tests and Measurements
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Test parameters for
Ω - Meter (7 mA):
Sound [On, Off]
Limit (R) Limit value selection: [
OFF, 1 Ω – 15.0 kΩ]
Ω - Meter (7 mA) measurement procedure:

Select the Ω - Meter (7 mA) measurement function.

Set the test parameters (sound and limit).

Connect the test leads to the instrument.

Compensate the leads (optional).

Connect the test leads to the test object.

Press the Run key to start the measurement.

Wait until the test result is displayed on the screen.

Press the Run key to stop the measurement.

Save results (optional).
Note:
 Consider displayed warnings when starting the measurement!
11.5.2.1 Compensation of test leads resistance
This chapter describes how to compensate test leads resistance in both continuity functions
(
Ω - Meter 200 mA and 7 mA). Compensation is required in 2-wire mode to eliminate the
influence of test leads resistance and the internal resistances of the instrument on the
measured resistance. The lead compensation is therefore a very important feature to obtain
correct result. Once compensation has been performed, the compensation icon
appears on the screen.
Circuits for compensating the resistance of test leads
Figure 11.59: Shorted test leads
Compensation of test leads resistance procedure:

Select the Ω - Meter 200 mA or 7 mA function.

Connect test cable to the instrument and short the test leads together see
Figure 11.59 .

Press the icon to compensate leads resistance.
Notes:

The limit value for lead compensation is 5 Ω.
 The lead compensation current is 200 mA DC.