Abstract: An accelerometer includes a silicon capacitive detector and an electronic device for measuring the capacitive unbalance of the detector, providing an output voltage representative of the acceleration. To avoid the perturbations caused by the stray capacitances present in the detector, there is provided a compensation system for injecting into the measurement system a predetermined correcting electric signal so that the output voltage of the accelerometer is substantially proportional to the ratio between the difference and the sum of the capacitances of the detector's capacitors.

Abstract: An electrostatically servo-controlled pendular micro-sensor includes a pendular element disposed so as to respond to a force representative of a physical quantity to be measured. To avoid the drifts affecting the stability of the micro-sensor, generated by the existence of unstable parasitic voltages that impair the voltages provided by a system servo-controlling the pendular element, the electrostatic forces generated to draw back the pendular element through servo-control voltages have a zero mean value. The control voltages are periodic voltages or series of electric signals of equal durations, each having, preferably, a zero mean value.

Abstract: A system is disclosed for measuring the angle of incidence of an aircraft, comprising at least one probe with a laser generator having a monochromatic emission spectral line, an optical emission system, an optical system receiving a monochromatic radiation back-scattered by the aerosols, means for pumping the laser generator, a detection interferometer receiving a part of the emitted laser beam and the back-scattered radiation and means for determining, after beating of the emitted beam and back-scattered beam, the Doppler frequency of the back-scattered beam and deriving therefrom the air speed along the axis of the emitted laser beam, in which system the optical emission system is adapted so as to focus the emitted beam on an air slice distant from the aircraft, the laser generator is disposed in the vicinity of the skin of the aircraft, the pumping means and the interferometer are moved inside the aircraft and the frequency of the laser spectral line is adapted so that the connections between the probe, on

Abstract: A method and device are provided for measuring the propagation time of a wave, wherein a wave is transmitted modulated in amplitude by a modulation signal. The wave reflected by an obstacle is received after a propagation time and the amplitude thereof is detected. The average value of the product of the detected signal and a reference signal is calculated and the delay with respect to the modulation signal is controlled so as to cancel out the average value. The modulation signal and the reference signal comprise a succession of elementary signals chosen so as to allow, in a single measurement, a long propagation time to be determined without ambiguity and with high accuracy.

Abstract: A differential pressure gauge comprises a balance beam (3) acting upon a vibrating blade (6). The beam (3) and the blade (6) are disposed in a rigid chamber 4 under vacuum. The beam (3) is acted upon by a force, resulting from the deformation of a flexible or expansible chamber (7) subjected to a pressure P.sub.T and disposed in a second rigid chamber (5) subjected to a pressure P.sub.S. A flexible or expansible seal element (9) isolates the chambers but transmits the forces without disturbing them. This gauge has a high precision and delivers information in digital form, particularly useful in aeronautics.

Abstract: A device for producing at the output of a multivibrator an electric signal the period of which is a linear function of a temperature to which is subjected the measuring probe, characterized in that said multivibrator consists in a comparator whose first input comprises the probe, said probe consists in at least two semi-conducting junctions connected two by two in parallel and in opposite directions, and the other components of the device, particularly those of the second comparator input comprising a capacitor, remains invariable.