Which instrument is used to test the resistance of wire insulation?

Which instrument is used to test the resistance of wire insulation?

• A. Ohmmeter
• B. Multimeter
• C. Megger
• D. Voltmeter

Answer: (C)

The instrument specifically designed to test the resistance of wire insulation is the Megger. This device applies a high voltage to the insulation and measures the current that flows through it. By calculating the resistance from this information, a Megger can determine the integrity of the insulation, ensuring it is functioning correctly and safely.

Meggers are particularly effective for identifying insulation breakdowns, which can lead to hazardous conditions if not addressed. This makes them vital for electrical safety testing and maintenance, as they provide insights into the insulation's performance under operational conditions.

The other instruments listed, such as Ohmmeters and Multimeters, are typically used for general resistance measurements in low-voltage applications and are not designed for the high-voltage testing required for insulation materials. A Voltmeter measures voltage rather than resistance, making it unsuitable for this specific purpose.