Clamp for measuring AC and DC leakage currents

A measurement clamp comprising:

• a fixed jaw and a moving jaw,
• wherein the fixed jaw comprises a first magnetic core entirely surrounded by a first magnetic shield and the moving jaw comprises a second magnetic core entirely surrounded by a second magnetic shield,
• the first and second magnetic cores being separated by two diametrically opposite air gaps each receiving a magnetic flux sensor, and
• an external flux-cancellation coil surrounds one or the other, or both, of the first and second magnetic shields,
• wherein the magnetic flux sensor is an AMR sensor consisting of four thin-film ferromagnetic resistors connected to a Wheatstone bridge, a flip coil and an associated control circuit enabling the polarity of an output voltage of the bridge to be reversed by applying current set and reset pulses to the flip coil.