KYORITSU 3127 - Manual (Page 26)

－ 23 －
6-5-2DAR - Dielectric Absorption Ratio
DAR measurement is almost same to PI measurement in a sense that they test
the time course of insulation. The only difference is that DAR measurement can
get result faster than the other.
DAR =
Insulation resistance
(1 min after a start of test)
Insulation resistance
(15 or 30 sec min after a start of test) *1
DAR 1.4 or more 1.25 - 1.0 1.0 or less
Criteria Best Good Bad
Note1: DAR time is selectable: 15 or 30 sec.
How to select:
①
Keep the MODE button( ) pressed down and rotate the Range switch to
power on KEW3127. (DAR mark starts blinking.)
② Press the UP/DOWN button ( ) to switch 15 sec and 30 sec displayed at
the lower left on the LCD. Select the desirable one.
③ Press the ENTER button ( ) and confirm the selection.
Selected DAR time is saved and kept after the instrument is powered off. To
check the time currently selected, follow the step ① described as above.
6-5-3 How to measure DAR/ PI
DAR and PI are measured automatically at continuous measurement of IR
PI/DAR
mode. Set the Range switch to any range and measure the test object continuously.
- 1 min after a start of continuous measurement:
LCD shows DAR value.
- 10 min after a start of continuous measurement:
LCD shows PI value.