Clamp-on current measuring probe and method of calibration of this probe

摘要

The clamp-on current measuring probe (2) is associated with a device (30) for calibration. This preferably comprises a calibration cable (14) arranged in the clamp closing gap (10), which is connected in series with a constant current source (38) via a current measuring device (32) and a calibration key (34). If the calibration key (34) is operated, a predetermined calibration current (IK) flows through the calibration cable (14). The measured current (I'M) indicated by the measuring device (24) is compared with the calibration current (IK) and if the two values differ, the clamp-on current measuring probe (2) is checked for the existence of an air gap (16) or other causes of the fault and the measured indication is corrected. IMAGE