Test Method Of Dar And Pi - PCE Instruments PCE-ITM 20 User Manual

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Test method of DAR and PI

Firstly, short press MAX/MIN in the Insulation switch, then press LOCK button. Secondly, press
INSULATION TEST button to start the test of DAR and PI. One minute later, the test results of
DAR will show on the screen. PI test results will show on the screen after 10 minutes.
The reference value of DAR and PI are as following:
PI Standard
2 ... 4 (typically 3)
PI Value
Tested Considered as
material good insulation
status (older types)
Example:
If the reading of B-class insulation material is 100M in 1minute, 110MΩ in 10 minutes,
polarization index is 1.1(110MΩ/100MΩ=1.1). As the insulating material contains too much
water or seriously polluted, the polarization index is below the minimum acceptable value, you
need to repair or replace parts.
DAR Standard
DAR Value
Tested material status
1 ... 1.5
Not acceptable
(older types)
1.6 or more 1.25-1.6
Excellent Pass
© PCE Instruments
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1
(very high insulation
resistance) Modern
type of (good)
insulation system
<1.25 OR less
Fail
1.0 or less
Fail