PeakTech 2680 A, Руководство по эксплуатации

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PI: Polarization index
The polarization index is a measurement method that considers the
measurement over the time. The measurements for calculating the
PI are recorded after 1 minute and the second measurement is
taken after 10 minutes. This long measurement time makes it
possible to determine the quality oft he isolator.
For the polarization index, the general rule is that a PI of 4 or higher
indicates very good insulation of the measurement object. A PI of 2
or lower indicates poor insulation of the measurement object. A PI
between 4 and 2 can indicate possible damage to the isolator.
Important: The measurement of the polarization index is only
suitable for solid insulation materials!
The calculation of the PI is as follows:
PI = Insulation resistance after 10 minutes / Insulation resistance
after 1 minute
The value of the PI has no unit.