Abstract: The invention relates to a method for detection of a leak from a tank for liquid gas, said tank comprising a membrane surrounding the liquid gas, the membrane being surrounded by an insulation space which separates the membrane from a wall, the insulation space being filled an inert gas which is injected and extracted by at least one duct. The detection method comprises the following steps: determining 921 a first variation of mass of inert gas ?M1 between two moments by measuring the gas added and removed by the duct; calculating 922 a second variation of mass of inert gas ?M2 corresponding to a difference between two masses of inert gas measured in the insulation space; and comparing 931 the first variation with the second variation, and triggering an alarm if a difference E1 between the first variation and the second variation of mass of inert gas is greater than a first threshold S1.

Abstract: The position of a tape loop in a vacuum chamber is capacitively detected. e capacitive detector includes a flexible electrode that is deflected between a pair of walls parallel to a wall of a vacuum chamber in which the loop is formed by differential pressure in the chamber and by the pressure of a vacuum source having a pressure between the two pressures in the vacuum chamber. Between the flexible electrode and a stationary electrode is a fixed, solid dielectric. The wall includes plural apertures forming separate fluid flow paths. The vacuum source includes a partition with a plurality of apertures forming separate fluid flow paths. The apertures of the wall and partition are aligned and positioned in a direction between opposite ends of the vacuum chamber.

Abstract: A separately excited D.C. motor employs an analog servo control responsive to a speed control input signal that controls the derivation of a compensating signal for the motor back emf. The speed control and compensating signals are combined to control the motor speed via an analog regulator. A digital shaft encoder responsive to the motor position supplies a pulsed signal to a comparator that is also responsive to a desired position signal that is derived from the speed control signal. The comparator derives an integrated error signal that is supplied to the analog regulator. Application of the speed control signal to the regulator is delayed if a thermal simulator for the motor characteristics indicates motor overheating. In response to the compensated, desired speed indicating signal indicating that the motor has been ordered to stop, the error signal is decoupled from the analog regulator.

Abstract: An indication is derived of the thermal properties of a constant load motor during acceleration and deceleration periods without actually monitoring thermal properties of the motor. The motor is accelerated and/or decelerated in response to command pulses so there is a rotational speed change during the acceleration and deceleration periods. In respnse to the command pulses, the charge on a capacitive means is changed so the charge change is proportional to (1) the change of the motor rotation speed during the periods and (2) the reciprocal of the periods. In response to the charge change there is derived an indication of the thermal properties as a function of the electrical, thermal and mechanical characteristics of the motor.