Abstract: A liquid container hydrostatic level gauge, in particular a fuel tank level indicator, which operates with a differential pressure sensor, a zero point calibration related to the height of the fuel is performed upon the beginning of measurement, in order to dispense with a requirement for temperature independence and long-term stability of the zero point of the differential pressure sensor. A meter tube is disposed in the container interior, extending from above the maximum liquid level to as far as the container bottom with an opening for receiving fuel within the tank. The differential pressure sensor is connected by one meter input to the upper end of the meter tube and by its other meter input is exposed to the air pressure acting upon the surface of the liquid. An air pump is connected to the upper end of the meter tube between the upper level of the fuel and the input to the pressure sensor. At the beginning of measurement, the meter tube is flooded, and an output value (U.sub.

Abstract: A circuit arrangement for transmitting variable measurement values, such as pressure and temperature, at vehicle wheels is provided which transmits the measurement values in the form of H-F signals to a stationary evaluating circuit (12) with great accuracy, high reliability and in short time intervals. A repeater coil (b 13), which is connected with the latter, arranged in the vicinity of the wheel so as to be stationary and connected to voltage by a square-wave generator (15), cooperates with a revolving repeated coil (19) which is fastened at the vehicle wheel and connected with a sensor circuit arrangement (20) supplied by it.

Abstract: To provide a rugged vibration and shock-insensitive position transducer, a coil is wound on a lamella-like carrier which has a body element of electrically insulating material on which, at least on one surface, a foil of magnetically highly permeable material is positioned; these lamella-foil combinations can be stacked, or a unitary body which foils on both sides can be provided. A short-circuit ring, movable along the core, changes the inductance of the coil wound thereon, the value of which can be determined by energizing the coil with alternating current.

Abstract: A pressure pickup for measuring the pressure in the intake manifold of an internal combustion engine. The pressure pickup comprises a part, movable in response to the manifold pressure, to which is coupled means for short-circuiting the magnetic flux lines of an electromagnet so that the change in flux lines is detected by the electromagnetic coil and measured by an induction evaluation circuit and thus indirectly measuring the manifold pressure.

Abstract: A moveable mass is part of a resilient spring system, in which the spring is a leaf spring restrained in a housing. Strain gauges are applied to the leaf spring, the outputs of which are integrated in a bi-polar integrator. Vibration of the leaf spring will cause sequential integration in reverse direction and, accordingly, a low output signal; deflection of the mass, for example upon on impact, will cause the integrator to provide a strong integrating signal which can trigger a collision safety system. The inherent, or characteristic frequency of the system is so selected that it is above the frequency occurring upon an impact of the sensor, or upon collision, but below the frequency occurring due to concussions to which the vehicle, or the mounting post of the apparatus on the vehicle, is subjected in use, or repair.