This category includes specialized measuring instruments for testing and evaluating the insulation performance of electrical equipment and electronic devices. These instruments measure insulation resistance values of motors, transformers, cables, control panels, and other equipment to verify electrical safety and equipment integrity. In manufacturing industries, they are used for maintenance inspections of production equipment, acceptance testing of new installations, and periodic insulation degradation diagnostics. The product lineup includes digital display types, analog pointer types, and models with data logger functions, supporting measurement voltages from 500V to 5000V according to application requirements. Unlike other electrical measuring instruments such as multimeters and clamp meters, these are specialized devices dedicated to insulation resistance measurement.