Abstract: Digital apparatus for controlling members by eddy currents comprising a sensor constituted by a primary winding and a secondary winding, an exciting sinusoidal voltage generator, a correcting circuit for eliminating the residual voltage supply by the secondary winding of the sensor, a circuit for analyzing the corrected measuring voltage incorporating two samplers and a means for displaying the two signals supplied by the two samplers. The exciting voltage generator is of the digital type and comprises an oscillator, a counter, a memory and a digital-analog converter. The collection circuit comprises a number selection means, a comparator, a counter, a memory and a digital-analog converter. The means for generating control pulses for the samplers comprises a number selection means, a comparator and a digital phase shifter.A particular application is in the field of non-destructive testing.