Abstract: The invention makes it possible to measure the degree of radioactive radiation emitted by large pieces. It includes two large gamma ray detectors (12A, 12B) placed opposite each other and whose spacing is adjustable. They are completed by a photoelectron multiplier (14A, 14B). The piece (2) to be measured is suspended so as to be brought between the two detectors (12A, 12B). The positioning of these detectors is obtained with the aid of a computer and a system (22) for recognizing the shape of the piece (2) functioning with the aid of optical clip-on lenses. The fact that the two detectors are position-adjustable makes it possible to take account of the shape of the piece to be measured. An application is the recovery of materials originating from nuclear installations with the view to re-using the materials.

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.