Sonel MPI-540 User Manual page 62

very high. Then, in accordance with the formulas from section 10.4.4, calculations
can be made to estimate the influence of measurement conditions. To reduce the
uncertainty of the δ, measurement, the contact of the probe with earth may be im-
proved, for example, by:
o moistening the spot where the probe is driven with water,
o driving the probe in a different location,
o applying an 80 cm probe.
Also, test the test leads for:
o whether their insulation is not defective
whether the lead – banana plug – probe contact areas are not corroded or loos-
o
ened.
In majority of cases the achieved measurement accuracy is satisfactory. However,
you should always take account of the uncertainty included in the measurement.

Factory calibration does not include the resistance of the test leads. The result dis-
played by the meter is a sum of the resistance of the measured object and the re-
sistance of leads.
Additional information displayed by the meter
>1.99 kΩ
R
E
60
The meter is ready for measurement.
Measurement in progress.
Too high voltage at the meter terminals.
Measuring range is exceeded.
Signal / noise ratio is too low (interfering signal too large).
Error due to the resistance of electrodes > 30 % (for cal-
culating uncertainty, measured values are taken into ac-
count).
Interruption in measuring circuit or resistance of test
probes is higher than 60 kΩ.
Interruption in the test probe circuit.
Interruption in the voltage probe circuit.
Too small test current.
No continuity in the current clamps circuit.
MPI-540 – USER MANUAL