An insulation resistance tester is a device used to measure the resistance of electrical insulation in cables, motors, and other equipment. It helps ensure that insulation is functioning properly and can prevent electrical faults, which can lead to equipment failure or safety hazards. The tester applies a high voltage to the insulation and measures the resulting current flow, providing a resistance value. These testers are essential for maintenance in various industries, including construction, manufacturing, and utilities. Regular testing can identify potential issues before they become serious problems, ensuring the reliability and safety of electrical systems.