Stromzangen

Stromzangen are devices used to measure electric current by clamping around a conductor without interrupting the circuit. The German term corresponds to the English “current clamp” or “clamp meter.” A typical Stromzange features two jaws that close around a single conductor, forming a magnetic circuit. When current flows, it creates a magnetic flux proportional to the current; sensing electronics inside the device convert this flux into a readable signal. Modern meters are often integrated into handheld digital multimeters, while standalone clamp meters are common in industrial settings. Some models measure alternating current (AC) only, while others measure direct current (DC) as well, and many offer true RMS processing.

Stromzangen vary in design and sensing method. Split-core clamps can be opened to place or remove a conductor without disconnecting the circuit, while solid-core models require threading the conductor through the jaw. Measurement technologies include transformer-based sensing for AC (or AC components) and Hall-effect sensors for DC and true DC measurements. Features differ by model and may include measurement ranges, accuracy classes, data logging, Bluetooth connectivity, and safety ratings.

Applications include electrical installation work, maintenance, troubleshooting, and energy auditing. They allow measurement of line currents in live systems with minimal risk and without breaking the circuit. For accurate readings, the clamp should enclose only one conductor; if multiple conductors are inside the jaw, readings reflect the net current and may be inaccurate.

Safety and standards: Stromzangen are designed to isolate the user from high voltage within specified limits and should be used according to the instrument’s CAT ratings and operating instructions. The concept dates to early 20th century development, with modern digital clamp meters becoming widespread in the late 20th century.