Insulation resistance tester is also commonly referred to as a megohmmeter or digital shaker



It is an electronic instrument specifically designed to measure the insulation resistance of electrical equipment, circuits, and materials. It is a key tool for ensuring electrical safety and evaluating the insulation performance of equipment (such as whether it is damp, aged, or damaged).

⚙️ Working Principle

The core principle of the insulation resistance tester is Ohm's law (R = U / I).

It generates a stable high DC voltage (commonly 250V, 500V, 1000V, 2500V, or even higher) through its internal circuit, applies it across the object under test, and then measures the weak leakage current (usually in the microampere range) flowing through the insulating material. Finally, it automatically calculates and directly displays the insulation resistance value in digital form (typically in megohms MΩ or gigohms GΩ).