What is the primary purpose of a meg-ohm meter, commonly referred to as a megger?

The primary purpose of a meg-ohm meter, or megger, is to test the effectiveness of insulation. This device is specifically designed to apply a high voltage to insulation material, allowing technicians to measure the resistance of the insulation. A high resistance reading indicates that the insulation is effective in preventing current leakage, while a low reading may indicate that the insulation is deteriorating or failing, which could lead to hazardous conditions.

In contrast, other options do not align with the megger’s function. Measuring electrical current involves using an ammeter, calibrating voltage levels usually requires a different type of equipment, and determining device power ratings typically entails using a power meter or similar device. Thus, the megger is uniquely suited for insulation testing, making answer choice focused on insulation the definitive and correct response.