What does a megger primarily measure?

A megger, also known as a megohmmeter, is specifically designed to measure high resistances in electrical systems. It operates by applying a high voltage across the insulation of wires and components, allowing for the assessment of insulation integrity and resistance to currents that typically exceed those that standard multimeters can measure.

This measurement is crucial for determining whether insulation is faulty, which can lead to equipment malfunction or safety hazards such as electric shocks or fires. The ability to measure high resistances helps linemen ensure that electrical installations and equipment maintain appropriate insulation levels, thereby contributing to overall safety and reliability in electrical systems.

In comparison, measuring voltage levels, current flow, or electrical frequency involves different types of instruments, such as voltmeters, ammeters, and frequency meters, each of which serves a distinct purpose in electrical diagnostics and monitoring.