Insulation tester calibration involves verifying and adjusting the accuracy of insulation resistance testers, which are used to assess the integrity of electrical insulation in cables, motors, transformers, and other equipment. The process includes checking the tester’s voltage output, measuring accuracy across different resistance ranges, and comparing readings against certified reference standards. Any deviations are recorded, and adjustments are made to ensure precise measurements. Regular calibration ensures reliable detection of insulation weaknesses, supports electrical safety, maintains compliance with industry standards, and provides traceable documentation for quality assurance and preventive maintenance programs.