Stromzange

Stromzange is the German name for what in English is called a current clamp or clamp meter. It is a portable electrical instrument used to measure current in a conductor without breaking the circuit. The core feature is a pair of insulated jaws that form a magnetic circuit; when the jaws surround a single conductor, the current generates a magnetic field proportional to the current. This field is sensed by a transformer in older devices or by a Hall-effect sensor in modern meters and converted to a readable display.

AC versus DC measurement: Older clamps relied on a current transformer and measured alternating current only; newer models can measure both AC and DC, with true RMS readings and higher accuracy. Most clamps require that only a single conductor passes through the jaws; if multiple conductors are enclosed, the net current may be incorrectly indicated. Many devices are digital, offering ranges, data hold, and sometimes temperature or voltage measurement as additional features.

Usage and safety: Stromzange are used by electricians and technicians for troubleshooting, load assessment, energy management, and preventive maintenance. They offer non-invasive measurement and quick checks, but must be used according to safety standards. Clamps are rated by electrical safety categories (for example CAT II/III/IV) and voltage/ampere ranges; incorrect use can lead to electric shock or equipment damage.

See also: Clamp meter, Electrical measurement, Hall effect sensor.