Which electrical tool is used to test insulation?

The megohmmeter, also known as an insulation resistance tester, is specifically designed to measure the insulation resistance of electrical wiring and components. It applies a high voltage to the insulation and measures the resultant current flow, determining the effectiveness of the insulation in preventing leakage current. This tool is critical for ensuring that electrical systems are safe and function correctly, especially in preventing short circuits and equipment damage that can arise from degraded insulation.

In contrast, a multimeter typically measures voltage, current, and resistance but does not specialize in insulation resistance testing at the high voltages needed for accurate readings. An oscilloscope is used for visualizing electrical signals and waveforms, making it unsuitable for insulation testing. A clamp meter is primarily used for measuring current flow in conductors without the need to disconnect them; it does not evaluate insulation integrity. Therefore, the megohmmeter stands out as the appropriate choice for testing insulation due to its design and application.