Insulation Resistance (IR) / Polarisation Index Measurements

IR/PI measurements are one of the most widespread basic diagnostic tests which determine the condition of rotating-machinery windings.

IR is the resistance value of the insulation after one minute of voltage appliance, while PI is a variation of IR and pertains to the ratio of the value of the electrical resistance after one minute and after ten minutes of voltage appliance.

The measurements obtained from this test service are a quick and reliable means to assess the overall condition of the winding as low IR values indicate a major insulation issue.