Abstract: A level gauge for a tank of a driven sensor type includes a drum around which is wound a thread on the end of which is suspended a driven level sensor. A reversible servomotor drives the drum with the drum being driveable in reverse directions. The rotation of the drum is recorded and a variation in the force of the thread is detected. The force is directly related to the relative position of the sensor with respect to the level being measured. The detector for detecting the variation in the force in the thread includes an element rotatably mounted about a horizontal axis, with an oscillation of the element being limited by a damping arrangement, with movement of the element enabling the force exerted on the thread to be measured.

Abstract: The present invention relates to a process and device for measuring the level and the specific gravity of a liquid e.g. liquified methane, contained in large-capacity tanks.The installation comprises two hydrostatic probes for spray a neutral gas into the tank, the first probe emerging near the bottom of the tank and the second slightly below the maximum filling level, a pressure differential/electric voltage transducer each of whose two inputs is connected to a hydrostatic probe, a system for numerically displaying the level and the specific gravity of the liquid contained in the tank, at least one pick-up capable of transmitting a signal when the liquid reaches the predetermined level in the tank, and a device for adjusting the value of the specific gravity of the liquid when the liquid reaches the predetermined level in the tank.