Abstract: The invention relates to a method for operating an ultrasonic sensor apparatus (3) for a motor vehicle (1), in which a diaphragm of a first ultrasonic sensor (4a) is excited to emit a first ultrasonic signal using a frequency-modulated first excitation signal (10a) and a diaphragm of a second ultrasonic sensor (4b) is excited to emit a second ultrasonic signal using a frequency-modulated second excitation signal, wherein the diaphragm of the first ultrasonic sensor (4a) and the diaphragm of the second ultrasonic sensor (4b) have the same resonant frequency (fR), wherein the first excitation signal (10a) comprises a first frequency range (fa) and the second excitation signal comprises a second frequency range (fb) that differs from the first frequency range (fa), wherein a temporal profile of a maximum amplitude (Am) of the first excitation signal (10a) and a temporal profile of a maximum amplitude (Am) of the second excitation signal are changed.

Abstract: An optical pumping and isotropic measurement magnetometer. The magnetometer is all-optical in the sense that resonance between Zeeman sub-levels is induced by modulating the intensity or the frequency of the pump beam. Resonance is detected either using the pump beam itself or an unmodulated probe beam. The pump beam is linearly polarised and its polarisation direction is kept constant relative to the direction of the magnetic field to be measured, so that a measurement independent of the orientation of the field can be made.

Abstract: The invention relates to a method for operating an ultrasonic sensor apparatus (3) for a motor vehicle (1), in which a diaphragm of a first ultrasonic sensor (4a) is excited to emit a first ultrasonic signal using a frequency-modulated first excitation signal (10a) and a diaphragm of a second ultrasonic sensor (4b) is excited to emit a second ultrasonic signal using a frequency-modulated second excitation signal, wherein the diaphragm of the first ultrasonic sensor (4a) and the diaphragm of the second ultrasonic sensor (4b) have the same resonant frequency (fR), wherein the first excitation signal (10a) comprises a first frequency range (fa) and the second excitation signal comprises a second frequency range (fb) that differs from the first frequency range (fa), wherein a temporal profile of a maximum amplitude (Am) of the first excitation signal (10a) and a temporal profile of a maximum amplitude (Am) of the second excitation signal are changed.

Abstract: A device for measuring an electric field in a conducting medium, including: two electrodes separated by a volume of an insulating material; a current measurement device; a voltage measurement device; and a switch enabling to alternately connect the current measurement device and the voltage measurement device between the electrodes.

Abstract: A device for measuring an electric field in a conducting medium, including: an insulating enclosure; first, second, and third pairs of electrodes, the electrodes of a same pair being arranged on opposite external walls of the enclosure, and the electrodes of the first, second, and third pairs being centered on first, second, and third orthogonal axes; a first conductive coil; a first pair of switches enabling to alternately connect the first coil between the electrodes of the first, of the second, and of the third pair of electrodes; and a single magnetometer.

Abstract: A device for measuring an electric field in a conducting medium comprises: two electrodes separated by a volume of an insulating medium; a device for measuring current coupled to said electrodes; and adjustment elements making it possible to vary a quantity on which the electrical conductivity of the field measuring device depends.

Abstract: An optical pumping and isotropic measurement magnetometer. The magnetometer is all-optical in the sense that resonance between Zeeman sub-levels is induced by modulating the intensity or the frequency of the pump beam. Resonance is detected either using the pump beam itself or an unmodulated probe beam. The pump beam is linearly polarised and its polarisation direction is kept constant relative to the direction of the magnetic field to be measured, so that a measurement independent of the orientation of the field can be made.

Abstract: A device for measuring an electric field in a conducting medium comprises: two electrodes separated by a volume of an insulating medium; a device for measuring current coupled to said electrodes; and adjustment elements making it possible to vary a quantity on which the electrical conductivity of the field measuring device depends.

Abstract: A device for measuring an electric field in a conducting medium, including: two electrodes separated by a volume of an insulating material; a current measurement device; a voltage measurement device; and a switch enabling to alternately connect the current measurement device and the voltage measurement device between the electrodes.

Abstract: A device for measuring an electric field in a conducting medium, including: an insulating enclosure; first, second, and third pairs of electrodes, the electrodes of a same pair being arranged on opposite external walls of the enclosure, and the electrodes of the first, second, and third pairs being centered on first, second, and third orthogonal axes; a first conductive coil; a first pair of switches enabling to alternately connect the first coil between the electrodes of the first, of the second, and of the third pair of electrodes; and a single magnetometer.