Polarization Index Calculator
Enter one-minute and ten-minute insulation resistance readings plus a reference PI value for a transparent ratio worksheet.
- Polarization index
- Reference margin
- Reference status
Calculation details
- Calculation basis
- Testing boundary
Recent results
Formulas
- Polarization index = 10-minute resistance / 1-minute resistance
- Reference margin = polarization index - entered reference PI
- Status = at or above reference when polarization index is greater than or equal to the entered reference
Use this calculator
Calculate the polarization index ratio and compare it with a user-entered reference value.
Read the result
Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.
Check before final work
This polarization index estimate is a ratio worksheet. It does not establish an acceptance criterion, verify test voltage, temperature correction, equipment condition, manufacturer rules, or safety procedures.
FAQs
Does this decide whether insulation passes?
No. It only compares the calculated ratio with the reference you enter. Equipment, test voltage, temperature, procedure, and qualified review still control.
Can PI be below the reference?
Yes. The calculator reports the arithmetic status against the entered reference without interpreting the cause or approving corrective action.