Abstract: A device for measuring a quantity of a superparamagnetic material includes four coils (1-4) and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The quantity of superparamagnetic material is derived from an amplitude of a component at a mixing frequency, which frequency is a linear combination of the frequencies of the two alternating currents. The device is designed to reduce the influence of stray electromagnetic fields and inadvertent signal offsets on the measurement results. The device may advantageously be used for immunoassays.

Abstract: A device for measuring a magnetic material includes four coils having cores made of a superparamagnetic material, and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The value of the magnetic field is derived from the value of the direct current required to cancel an amplitude of a component at a mixing frequency. A structure of the electrical connections to the coils reduces disturbances caused by the alternating currents used with respect to the detection of the component at the mixing frequency. Moreover, specific configurations of the coils reduce the influence of stray electromagnetic radiation on the measurement results. The device can also be used to measure direct currents.

Abstract: A device for measuring a magnetic material includes four coils having cores made of a superparamagnetic material, and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The value of the magnetic field is derived from the value of the direct current required to cancel an amplitude of a component at a mixing frequency. A structure of the electrical connections to the coils reduces disturbances caused by the alternating currents used with respect to the detection of the component at the mixing frequency. Moreover, specific configurations of the coils reduce the influence of stray electromagnetic radiation on the measurement results. The device can also be used to measure direct currents.

Abstract: A device for measuring a quantity of a superparamagnetic material includes four coils (1-4) and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The quantity of superparamagnetic material is derived from an amplitude of a component at a mixing frequency, which frequency is a linear combination of the frequencies of the two alternating currents. The device is designed to reduce the influence of stray electromagnetic fields and inadvertent signal offsets on the measurement results. The device may advantageously be used for immunoassays.

Abstract: A dental radiography device has an X-ray sensor (12) with a sensitive surface (22) for detecting X-rays and oriented towards the front face (16) of the sensor and a device for positioning the sensor made up of a receiver (32), for receiving the sensor, and an oblong arm (34) with an end (35) fixed to the receiver and an outwardly directed portion (34B) extending towards the front of the sensor and intended to extend out of the mouth of a patient, the receiver contained in a rear cylindrical space (33B) extending at the rear of a rear face (18) of the sensor opposite the front face (16), the rear cylindrical space (33B) defined by movement, along a lateral edge of the sensor, of a generating straight line (333) perpendicular to the sensitive surface.

Abstract: The dental radiography device comprises an X-ray sensor (12) which comprises a sensitive surface (22) which is capable of detecting X-rays of an X-ray beam, the sensitive surface (22) being oriented towards a front face (16) of the sensor and a device for positioning the sensor comprising a receiver (32) for receiving the X-ray sensor (12), and an oblong arm (34) which comprises an end (35) fixed to the receiver (32) and an outwardly directed portion (34B) which is located in front of the sensor (12) and which is intended to extend out of the mouth of a patient. The receiver (32) is contained in a rear cylindrical space (33B) which extends at the rear of a rear face (18) of the sensor (12), opposite the front face (16), the rear cylindrical space (33B) being defined by the movement, along a lateral edge of the sensor (12), of a generating straight line which is perpendicular relative to the sensitive surface (22).

Abstract: A radiodiagnosis apparatus for taking panoramic and tomographic pictures of an object, comprising an X-ray source and an X-ray receiver with a secondary slot for the passage of the received X-rays and downstream of a scintillator screen converting received X-rays into visible light, a sensor for transferring electric charges stored in the image elements from one line to the next one, fixedly mounted in the receiver to have its image zone corresponding to the opening of the secondary slot, means for controlling the charge transfer by the shift of the lines of charge at a frequency simulating the motion of a conventional radiographic film behind the secondary slot and a data processing device, the control means comprising a part movable behind the secondary slot at the speed of a radiographic film and a detector for the speed of that movable part and a unit converting the detected speed into an equivalent frequency of line shift of the charge transfer sensor.