Clamp for measuring current circulating in conductors

A clamp for measuring an electric current flowing in conductors, the clamp comprising first and second jaws (1, 2) interconnected by a hinge axis (3) to be movable between a closed position and an open position, the jaws being provided respectively with first and second annular magnetic circuit segments (4, 5), each segment (4, 5) having a proximal end (7, 8) and a distal end (9, 10) relative to the hinge, and at least the first segment (5) being mounted to rock about a rocker axis (6) parallel to a hinge axis (3), the clamp including spacer means (12) for spacing the proximal ends (7, 8) apart, which spacer means are active at least when the distal ends (9, 10) are spaced apart by a distance that is greater than or equal to a predetermined safety distance.