Abstract: A controller has two shunt lines connected in parallel with safety relays. For testing their switching capability, the safety relays are reversed to their idle positions and the change in voltage is monitored on their idle contacts. If voltage is missing, an error signal is issued. During the test, the parallel shunt line is closed so that the safety power line is not interrupted. Switching amplifiers having a response and action time which is a fraction of the preset response time of the safety relays control the safety relays. For testing the electrical control, the drives of the safety relays are switched to currentless and the change in voltage is monitored on the drives. If the change in voltage is inadequate, an error signal is issued. The safety relays remain in their operating positions during the test.

Abstract: A measuring instrument (11) for fill level sensors (4) having a measuring electrode (6) and a compensating electrode (9). The measuring instrument (11) has a bridge circuit whose one bridge branch (21) is formed by two series-connected test resistors (23, 24). The other bridge branch (22) is formed by the measuring resistor (17) on the measuring electrode (6) and the compensating resistor (18) on the compensating electrode (9). Between the two bridge branches (21, 22) a diagonal line (26) with a test switch (27) is provided. The measuring instrument (11) is controlled by the control circuit (13) so that the diagonal line (26) is closed outside of preset test time periods, and interrupted at preset test time periods. The end of the diagonal line (26) located between the two test resistors (23, 24) is connected to the base potential (25) of the measuring circuit (12).

Abstract: The bimetallic plates of the steam trap disclosed each comprise three same-direction active arms next to one another extending transversely to a center line. On the center line two active arms extend in opposite directions to one another and transversely to the other active arms. On the side of the bimetallic plates which curve concavely when deflected there are provided projections as support portions or faces for the active arms. The projections of at least two active arms project beyond those of the other active arms. The projections of the active arms come into effect at different temperatures and with accumulative force. The bimetallic plates therefore have a closing force line closely adapted to the saturated steam curve.

Abstract: The valve housing can be used for valves and steam traps with a compact automatic control unit. It has a connecting part with two flow ducts and a base on which the open end of a cap rests tightly. Two post-like projections with fastening orifices are provided on the longitudinal axis of the flow ducts on the connecting part next to the base and the cap. The cap has two laterally projecting screw bearings. They are arranged at a distance from the open end of the cap in front of the ends of the projections on the longitudinal axis of the flow ducts and are provided with screw holes. The cap is connected to the connecting part by two fastening screws which penetrate through the screw holes and are screwed into the fastening orifices of the projections.

Abstract: A shutoff valve with a spring-loaded valve disk. The spring, designed as a tension or pressure spring is arranged outside of the valve housing, where a pivoting arm is attached to the actuating shaft. One end of the arm remote from the shaft is engaged by the spring. The other end of the spring is supported on an abutment mounted on the outside of the valve housing. The driver and the abutment are arranged in such a way that in the closed position, an imaginary connection line extends between the abutment and the driver with a lateral displacement transverse to the longitudinal shaft axis extending in the direction of closing the valve. The operational state of the spring is always visible so that a damage or defect can be readily identified.

Abstract: The system provides for one single cable with four electrical conductors (16 to 19). Two of the conductors (18, 19) form a field bus line for the signal transmission, and the other two conductors (16, 17) form an energy line for providing energy supply. All signal transmitters (1, 2) and signal receivers (3, 4) are connected to the cable, and the cable (16-19) is fitted at both ends with a line termination (20-22). Each signal transmitter (1, 2) and each signal receiver (3, 4) has a field bus controller (8, 10). The entire signal transmission takes place via the two-wire field bus line (18, 19).

Abstract: In cases of application where the critical temperature occurs or could occur, safe monitoring of the level of the liquid was not possible heretofore because the physical properties of the liquid and of the gaseous medium present above the latter in the container no longer differ at this temperature. The method includes the temperature in the container in the monitoring of the level of the liquid. Below a lower comparative temperature value (Tu), the output signal of the evaluator unit is determined by the measuring signal of the level sensor. The measuring signal of the level sensor is disregarded above this value (Tu). The evaluator unit supplies an output signal that is on the safe side with respect to the level of the liquid. The comparative temperature (Tu) is below the critical temperature to an extent such that the inaccuracies in the measurement of the level sensor and the temperature sensor have no interfering effect.

Abstract: A probe for monitoring a medium within a container, which includes a mounting housing for mounting the probe on a container, a neck part attached at one end to the mounting housing, and at the other end to a radially cantilevered head housing. The head housing extends on only one side of the neck part. A sensor is attached to the mounting housing. An electrical conductor is attached to the sensor and extends through the neck part and into the head housing where it is connected to an electronic circuit, which is mounted inside the head housing. The head housing is made so that its dimensions in the radial direction of the neck part are greater than the dimensions of the neck part. The cantilevered mounting of the head housing allows heat from the container to dissipate into the atmosphere without contacting a significant portion of the head housing. The configuration of the head housing also allows easy access to the electronic circuit, even if two probes are placed in close proximity to each other.