Functional description
34
Testboy
®
TV 431
The highest, lowest and average value
When working in test mode, you can display the highest, lowest and average value using the SELECT button. When
working in data hold mode, you can display the values with the SELECT button.
Differential Absorption Ratio (DAR) and polarization index (PI)
There are cases in which no further intact isolation parts (which e.g. have lost their isolating effect under high voltage)
but which still present a good absorption ratio (or a good polarization index). The absorption ratio (polarization index)
can only be used to ascertain local isolation damage; they offer no indication as to dampness and contamination.
R10Min= resistance value measured 10 minutes after applying the test voltage; R1Min=R60Sec= resistance value
measured 1 minute after applying the test voltage; R15Sec=
resistance value measured 15 seconds after applying the
test voltage
After completing the insulation test, press the SELECT button to display the DAR and PI values. Should the DAR and PI
values be invalid, the display will show - - - -.
PI
(polarization index) =
Min
R
Min
R
1
10
DAR
(absorption ratio
)
=
Sec
R
Sec
R
15
60
