Abstract: A single-torus ohmmeter for measuring a loop impedance Zx, includes a single transformer having a primary winding of Np coils and a secondary winding of a single coil forming the measurement loop, in which, to compensate for a stray induction produced by an AC leakage current circulating in the measurement loop without canceling a measurement current Ip generating an alternating induction of constant average value for the measurement of the loop impedance Zx, the transformer includes a second secondary winding of Na coils whose output voltage Ub representative of the AC leakage current is delivered to a processing module providing a voltage intended to be added to an alternating measurement voltage Vp in an adder delivering the current to be injected into the primary winding after passage through a voltage-current converter.

Abstract: A single-torus ohmmeter for measuring a loop impedance Zx, includes a single transformer having a primary winding of Np coils and a secondary winding of a single coil forming the measurement loop, in which, to compensate for a stray induction produced by an AC leakage current circulating in the measurement loop without canceling a measurement current Ip generating an alternating induction of constant average value for the measurement of the loop impedance Zx, the transformer includes a second secondary winding of Na coils whose output voltage Ub representative of the AC leakage current is delivered to a processing module providing a voltage intended to be added to an alternating measurement voltage Vp in an adder delivering the current to be injected into the primary winding after passage through a voltage-current converter.

Abstract: A single-torus ohmmeter for measuring a loop impedance Zx, includes a single transformer having a primary winding of Np coils and a secondary winding of a single coil forming a measurement loop of impedance Zx, in which, to compensate for a stray induction produced by a DC leakage current circulating in the measurement loop without canceling a measurement current Ip generating an alternating induction of constant average value for the measurement of the loop impedance Zx, the transformer includes a second secondary winding of Na coils whose output voltage Ub is delivered to a processing module providing a voltage intended to be added to an alternating measurement voltage Vp in an adder delivering the current to be injected into the primary winding after passage through a voltage-current converter supplying current to the primary winding via a shunt resistance.