© PCE Instruments
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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
PI Value
2
… 4 (typically 3)
1
… 1.5
1
1.0 or less
Tested
material
status
Considered as
good insulation
(older types)
Not acceptable
(older types)
(very high insulation
resistance) Modern
type of (good)
insulation system
Fail
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
1.6 or more
1.25-1.6
<1.25 OR less
Tested material status
Excellent
Pass
Fail
Summary of Contents for PCE-ITM 20
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