Abstract: The invention relates to a device for controlling a material, said device comprising at least means for transmitting an electromagnetic signal at a carrier frequency Fp to illuminate the material and means for receiving the electromagnetic signal, characterized in that said device further comprises first means for modulating the electromagnetic signal at a frequency Fm1, said modulation means being arranged, on the signal path, between the transmission means and the material in order to spatially sample the emitted electromagnetic signal; second means for modulating the electromagnetic signal at a frequency Fm2, said modulation means being arranged, on the signal path, between the material and the electromagnetic signal reception means in order to spatially sample the electromagnetic signal passed through the material.

Abstract: A device determines at least one characteristic of electromagnetic radiation emitted from a test object. A support receives the object. A network of probes is distributed along a substantially circular arc, and the support is disposed in a plane formed by the network of probes or in a plane parallel to the plane formed by the network of probes. The network of probes or the support is pivoted in the plane formed by the network of probes or in the plane parallel to the plane formed by the network of probes about a point located in that plane to vary an angle formed between a given one of the network of probes and the support, and thereby allow measurements to be taken at plural angular positions of the network of probes relative to the test object.