The hipot tester, short for high potential, is a nondestructive test used to determine the quality of electrical insulation. During the test, high-voltage is applied to all devices for a fixed amount of time. This process determines if the insulation is marginal or not marginal. Hipot testers are beneficial for finding damaged insulation, stray wire strands, conductive or corrosive contaminants, terminal spacing problems and tolerance errors.

Due to the tester’s usage of high voltages and currents, accuracy of the instrument is of extreme importance. If a hipot tester encounters too high of a voltage, the safety of the equipment and the technician is threatened. In order to avoid a disastrous situation, calibration of a hipot tester should be performed frequently. By performing regular calibrations, the overall accuracy and reliability of the instrument will be assured.


Developing a schedule for your hipot tester’s calibration is crucial. Hipot testers should be calibrated regularly to ensure that the instrument is functioning to the best of its ability. Schedules should be created based upon the manufacturer’s recommendation and also on how frequently the tester is used. Hipot tester calibration will vary for each device; therefore, it is high recommended to calibrate your hipot tester based off of your personal usage more so than the manufacturer’s recommendation. Notably, hipot testers should always be calibrated during the following situations:


Hipot testers that are calibrated on a regular schedule reap many benefits such as:


Hipot testers that are calibrated are easier to trust. Due to the instruments involvement with high voltage and currents, it’s important to be able to trust the instrument will not malfunction when it’s come time to use it. Testers that are calibrated have been checked for corrections and uncertainties and are certified to indicate there are no issues.


Testers that have been calibrated are more likely to have accurate measurements. During calibration, technicians calculate measurement uncertainties and ensure the hipot tester is within an acceptable margin of error.


When a hipot tester is calibrated, readings from the instrument are more likely to be consistent with other measurements. Repeatability is vital for any instrument having to do with measurements. When measurements show consistency, it means the instrument is operating accurately and reliably.


Hipot tester calibration should always be performed by a professional. This is because hipot testers can be extremely dangerous if put into the wrong hands. Hiring a technician who is experienced will give you the best calibration results. Choosing an accredited calibration, with hipot testers included in their scope, is highly recommended. Accredited calibration labs will provide you with the most accurate calibration results, a certificate of calibration ensuring there are no issues and also traceability through NIST.

Should you be calibrating your own hipot tester?
Find out in this guide.