16
PI/DAR mode (Models 877 & 876 only)
PI (Polarization Index) is the ratio of the 10-minute insulation resistance to the 1-minute
insulation resistance.
DAR (Dielectric Absorption Ratios) is the ratio of the 1-minute insulation resistance to
the 30-second insulation resistance.
A general guide to interpret the PI or DAR test results are:
Insulation Condition
PI (Polarization Index) DAR (Dielectric Absorption Ratios)
Dangerous
<1.0
-
Questionable
<2.0
<1.3
Good
<4.0
<1.6
Excellent
>4.0
>1.6
Press the
PI/DAR button momentarily to enable PI mode with the LCD annunciator
turned on. Press momentarily again toggles to the DAR mode with the LCD annunciator
turned on. The secondary display shows the measuring lap times of
10’00” and
01’00” for PI and DAR modes respectively.