TENTECH MD-5075x, User Manual

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7.1. Measurement of the Dielectric Absorption
Index (DAI)
When pressing the key during the test, the Dielectric Absorption
Index (DAI) value will be exhibited on the display. It is only possible to
apply this function after a minimum of 1 minute of measurement; in case
the key is pressed before this minimum limit, the display will show the
message of value exhibition of DAI value, but will not show any value.
The polarization index is the quotient between the values of the insulation
resistance measured at the 60 and 30 second, and it is useful for
preventive and predictive maintenance of windings (present in
transformers, motors, generators, etc.).
=
DAI
R
R
60 seconds
30 seconds