Abstract: A search gas detector for leak detection instruments includes a gas inlet, a vacuum pump, and an apparatus by which the presence of a search gas is recorded. The vacuum pump is able to pump all reactive gases and the search gas recording apparatus is able to detect enrichments of the search gas. More preferably, the gas inlet is effective for permitting only the search gas to pass therethrough, the detector having a pair of chambers, the first to which the gas inlet and search gas apparatus are connected, and the second to which the vacuum pump is connected. The two chambers are interconnected by a constrictive line with the first chamber having a relatively large volume in relation to the second chamber.

Abstract: The invention relates to a process for operating a controlled heat conductance vacuum gauge with a measuring cell (18) comprising a Wheatstone bridge (1) with supply voltage (12, 13) and measurement voltage terminals (14, 15), a power supply and measuring instrument (21) and a connecting cable (19) containing several conductors and to a circuit therefor; in order to prevent errors of measurement caused by connecting cables (19) of different lengths and to automate cable length equalization it is proposed that the voltage of a power supply terminal (12, 13) of the Wheatstone bridge (1) in the measuring cell (18) be recorded without current via one (26) of the conductors of the connecting cable (19) and taken into account in the formation of the measurement value.

Abstract: The invention relates to a process for operating a regulated heat conduction vacuum gauge with a Wheatstone bridge (1) powered by a controllable supply voltage and a gauge filament (6) and a resistance (9) as two of its components among others, designed to be temperature-dependant to compensate for interference effects of the ambient temperature on the gauge filament (6) and to a suitable circuit for implementing this process; it is proposed, in order to improve and simplify the temperature compensation, that, by linking various electrical measurements of the bridge (1) or by equivalent approximation systems, the value or the temperature of the temperature-dependant resistance (9) be found and taken into account in determining the pressure measurements (drawing FIG. 2).

Abstract: A gas friction pump with rotor and stator, a motor for driving the rotor, and a circuit serving as a power supply to the motor, the circuit having electronic components for representing the current drawn by the motor.

Abstract: The invention relates to a measured value pickup for vacuum measurements, with the pickup including a sensor as well as electronic circuits for supplying the sensor with voltage, and a signal processing device. In order to be able to employ the measure value pickup independently of the location of the measured value processing system, it is proposed to configure it as a transmitter.