Measuring Polarization Index And Dielectric Absorption Ratios - Fluke 1508 User Manual

1508
Users Manual
Figure 7. Measuring Insulation Resistance
14
Measuring Polarization Index and
Dielectric Absorption Ratios
Polarization Index (PI) is the ratio of the 10-minute
insulation resistance to the 1-minute insulation resistance.
Dielectric Absorption Ratio (DAR) is the ratio of the
1-minute insulation resistance to the 30 second insulation
resistance.
Insulation tests should only be performed on de-energized
circuits. To measure the polarization index or dielectric
absorption ratio:
1. Insert test probes in the V and
Because of the time required to perform the PI
and DAR tests, use of test clips is recommended.
2. Turn the rotary switch to the desired test voltage
position.
Press the A C buttons to select polarization
3.
index or dielectric absorption ratio.
4. Connect the probes to the circuit to be measured. The
bbv05f.eps
Tester automatically detects if the circuit is energized.
input terminals.
COM
Note