Klemmemåler

Klemmemåler is a handheld electrical measuring instrument that determines current by clamping a hinged jaw around a conductor without disconnecting it. The device measures the magnetic field generated by the current flowing through the conductor, allowing users to obtain a reading without direct contact with live wiring. Modern klemmemålere often combine current measurement with other functions for broader electrical testing.

The measurement principle depends on the type of clamp sensor. Traditional clamp meters use a current transformer core around the conductor, while many contemporary models employ Hall effect sensors to detect magnetic flux. AC current can be measured directly, and DC current is detectable in models equipped with Hall sensors. Some meters provide true RMS readings to handle non-sinusoidal waveforms, and higher-end units may offer measurements of voltage, resistance, continuity, and other electrical parameters.

Common features include auto-ranging, a digital display, data hold, backlight, and memory or Bluetooth connectivity for logging and external viewing. Safety ratings (such as CAT classifications) and jaw size influence suitability for different electrical environments. Availability ranges from compact consumer models to professional instruments capable of measuring large currents.

Typical applications involve troubleshooting electrical installations, motors, panels, and circuits where opening the circuit is undesirable or impractical. Limitations include the inability to measure current accurately when more than one conductor passes through the jaw, and the need to observe proper safety procedures to avoid electric shock or arc flash. Klemmemålere are valued for quick, noninvasive current measurements and are widely used by electricians, technicians, and engineers.