Abstract: A device for dynamic measurement of the clearance between the tips of rotating blades and the stator of a rotary machine comprises a capacitive sensor polarized by a direct voltage and conditioned by a continuously polarized load amplifier having a high-pass filter structure, preferably of the second order. The construction of the sensor and of the cable connecting it to the conditioning device is coaxial. The calibration of the measuring chain can be performed theoretically, without having recourse to any testing.

Abstract: The apparatus for detecting impurities in a fluid circuit has a body member associated with a fluid conduit or reservoir which defines a detection zone. A magnet is associated with the body member and communicates with the fluid in the detection zone to attract metallic impurities. Fiber optic members extend from opposite sides of the detection zone, with one of the fiber optic members associated with a light source and the other fiber optic member associated with a light sensor. The light is transmitted by the first fiber optic member into the fluid in the detection zone. The light passing through the fluid is transmitted by the second fiber optic member to the light sensor.

Abstract: A first processing circuit receives signals from a vibratory acceleration and a speed of rotation and position sensor and comprises integration and filter means for providing a signal (sb) representative of the amplitude of any untrue running. A second processing circuit receives the output signal (sw) from the speed of rotation and position sensor and the signal (sb) and includes means for determining the phase difference between the signals (sw) and (sb). A memory (33) stores information representative, for different revolving systems and/or test conditions, of the difference between the measured phase difference and the angular position of an imbalance causing untrue running with reference to an origin on the revolving system. Appropriate information is read from the memory and combined with the measured phase difference in response to the actuation of selection means to provide an accurate output of the angular position of any imbalance causing untrue running.