Abstract: A transducer comprising a flexible piezoelectric layer as a sensor element for measuring mechanical quantities in hollow bodies, above all pressures in pipes, the opposite sides of this layer being bonded to electrically-conductive contact layers and being connectable via leads to a display and evaluation unit. In order to achieve a high temperature stability in such transducers and to make them suitable for use at temperatures exceeding 80.degree. C., the piezoelectric layer is proposed to consist of wurtzite or sphalerite. One of the electrically-conductive contact layers can be of some heat-resistant, flexible supporting material, for instance flexible metal foil, such as Cu-Be foil, or a sheet of plastic, one or both of whose sides are metallized, and the other electrically-conductive contact layer can be a metal coating applied by evaporation.

Abstract: A test volume and a reference volume are irradiated by separate beams of an infrared source, and the two beams are subsequently fed to a detector in periodical alternation. The time constant of the detector is small compared to the period of this alternation. From the measured differences in intensity the masses of the absorbing components of a sample in the test volume are determined. During each period the value of the detector signal is sampled by an evaluation unit at least once while either the test beam or the reference beam is being present at the detector. For separate determination of different sample components, radiation of different defined frequency bands is fed to the detector during each period, and the intensity of the test beam is determined at each of the different frequencies whereas that of the reference beam is determined at one of these frequencies at least.

Abstract: For a continuous measurement of the mass of absorbing particles in a gaseous sample, the sample is traversed by electromagnetic radiation of a wavelength greater than the mean radius of the particles. The difference in absorption for at least two frequencies is determined and appointed to the particle mass sought after.

Abstract: An axial fan, preferably for the cooling systems of water-cooled internal combustion engines, comprises an impeller and an air duct housing provided with a fan guard which is separated by an annular gap from the tips of the impeller blades and is centered on the impeller axis by a support comprising radial arms attached to the fan guard. For noise reduction, the radial arms are supported on the hub of the impeller, on the side facing the fan shaft, by means of a roller bearing held by a mounting plate, and the mounting plate is made independent of the impeller bearing.

Abstract: Capacitive measuring transformer, especially for small capacitance values, with two parallel bridge arms, connected with an oscillator, each of which has at least one capacitor, whereby a differential amplifier is provided which is connected on the input side with the bridge arms and the input of which is connected by a feedback circuit, containing passive elements only to one of the bridge arms. A control element (D.sub.1, D.sub.2) precedes every one of the bridge arms and a fixed potential or a potential changing inversely in relation the outlet of said differential amplifier, (OA.sub.1) is applied to the second bridge arm. As a result, one will moreover achieve a high measure of stability and linearity between capacitance and output voltage. The fixed potential is used when the feedback is to one bridge arm only. The potential changing inversely in relation to the output of the differential amplifier (OA.sub.

Abstract: The device comprises an evaluation unit and at least one transducer for feeding the electric signal to this unit on the occurrence of a characteristic event and the evaluation unit comprises a recognition unit sensing the occurence of the characteristic event. To permit determination of the trigger point characterizing the occurrence of the characteristic event also in the case of heavily noise-contaminated measuring signals the evaluation unit is provided with one or several comparators in addition to the recognition unit, whose thresholds are spaced out over a certain range of levels, and--depending on whether the transducer signal has reached the threshold of the recognition unit--by using the information contained in the evaluation unit, which is influenced by the sequence of the comparator responses according to the signal shape delivered by the transducer, for determination of the trigger point characterizing the occurence of the characteristic event, in a manner predetermined in the evaluation unit.

Abstract: An AC generator may be connected to the signal leads of a piezoelectric transducer in order to induce mechanical vibrations in the transducer via the inverse piezoelectric effect. For determination of the vibration characteristics of the transducer provisions are made for a subtraction unit, whose one input is fed with the excitation signal of the AC generator while the other input is connected to the signal leads of the transducer. An evaluation unit is connected to the output of the subtraction unit; it displays and processes the measurement signal derived as the difference of the response signal of the transducer and a signal proportional to the excitation signal.

Abstract: In order to improve in a simple manner the ventilation of a water-cooled internal combustion engine having a sound-absorbing cover, a suction device is provided at the air inlet opening of the cover, the suction device containing a suction port in the low pressure area of the radiator/fan assembly. By specific placement of several air inlet openings a variety of cooling requirements may be met.

Abstract: A pressure measuring device is provided with a change-over valve connecting the pressure sensor either with the pressure to be measured or with a reference pressure. The change-over valve is actuated by a separate control pressure and will protect the pressure sensor from the influence of the pressure medium to be measured in the spring-loaded idle position of the valve.

Abstract: In order to avoid the danger of overheating the separate exhaust jacket of a water-cooled internal combustion engine with a sound-absorbing cover whose enclosed space contains air inlet and outlet openings sealed against the penetration of sound, and is ventilated by cooling air during operation of the engine, and which has a separate exhaust jacket with air ducts of its own-with a radiator cooling fan being placed outside of the cover in the vicinity of a cover wall serving as a radial deflector for the outgoing air from the fan, and with the exhaust jacket leading substantially upwards from its outlet to its inlet opening-after the engine has been switched off and the forced ventilation has thus come to a standstill, the air inlet opening leading into the exhaust jacket is connected to the topmost part of this jacket and is positioned such as to be exposed to the flow of outgoing air from the fan.

Abstract: A partitioning circuit will partition into subintervals the time interval between two signals delivered by a recognition circuit, and will activate a gate circuit during one of these intervals which has been predetermined. In addition to the recognition circuit, the sequence of signals from a sensor responding to the occurrence of an at least approximately periodic event, is fed to a comparator circuit which will transmit a pulse to the gate circuit each time a certain signal level has been exceeded. If the gate is active, this pulse will be available for further processing.

Abstract: An apparatus is disclosed, for measuring the angular position of a shaft of a machine at the occurrence of an event originating from the operation of the machine, relative to a reference position of the shaft. The apparatus comprises a first sensor responsive to the reference position of the shaft (signal II) and a second sensor which, on the occurrence of the event, produces an output pulse and which produces a number of interference pulses in the periods between production of the output pulses (signal I). A comparator (4) having a threshold value which is capable of being exceeded both by the required pulses and the interference pulses, and a recognition circuit (3,6) which is adapted to recognize output pulses produced on the occurrence of the event, are arranged to control an evaluation circuit such as a counter (10). The evaluation circuit ascertains, e.g.

Abstract: The measuring electrode to be checked is polarized cyclically with an alternating voltage and the maximum amplitude of the electrode current as occuring during cyclical polarization is directly used as a measure for the metrologically relevant condition of the electrode.

Abstract: In addition to having at least one piezoelectric sensor element, a transducer is provided with at least one further measuring element, which is influenced by the state variable to be measured in the same way as the piezoelectric sensor element, and has its own signal lead.The additional measuring element may also be a piezoelectric element which may be excited so as to produce mechanical vibrations by utilizing the inverse piezo-effect, the change of the vibration characteristics of the vibration system consisting of the excited piezo-element and its environment serving as a measurement value for a static or quasi-static measurement.

Abstract: An internal combustion engine whose engine unit support, comprising such sound-generating parts as cylinders, cylinder head, piston rods, crankshaft bearings, crankshaft, is provided with a bracket of at least two arms at least at its output end. This bracket is attached to the bearing seats of the crankshaft and is provided with at least one sound-insulating element at each end of its arms for connecting said engine unit support to the crankcase. This will reduce any relative movements between the crankshaft and the crankcase in a simple manner.

Abstract: A device for ascertaining the internal pressure in a pressure system, particularly in a fuel injection pipe system, wherein the pressure to be measured is contained within an element which includes at one point a wall portion of reduced thickness so as to act like a membrane, and wherein a sensor device is included which is positionable in engagement with the membrane-like wall portion to detect any elastic deformation and variation of the membrane caused by the influence of the internal pressure.

Abstract: A transducer with a flexible sensor element for measurement of mechanical values, at least one flexible piezoelectric sensor element being provided for piezoelectrical or capacitive measurement, the opposite surfaces of the sensor element being at least partially connected to electrically leading contact surfaces.

Abstract: The oil pump of an internal combustion engine having an engine unit support elastically suspended in a crankcase, is arranged in a front wall of the crankcase and actuated by a flexible shaft driven by the crankshaft of the engine. Thereby, a vibrational decoupling between the engine unit support and the crankcase is ensured and a ducting of the pressurized oil out of the crankcase is simplified.

Abstract: The particulates content of exhaust gases is determined by a sampling device connected to the exhaust supply line. The particulates in the exhaust gases are deposited onto a gas-permeable filter material and the particulates determined by light reflected from the filter material. A constant differential exhaust gas pressure is maintained and a predetermined sample volume per time unit is metered to the filter material. The total cross-section of the exhaust-gas flow through the measuring device is maintained constant. The sampling is taken in short consecutive intervals at a rate such that the characteristics of dynamic changes in the particulates content of the exhaust gas can be determined.

Abstract: A transducer device for measuring mechanical values on hollow bodies, such as the internal pressure in pipes, by detecting deformation in the outer surface thereof, comprises a housing for removably enclosing the hollow body whose outer surface deformation is to be measured and at least one elastic sensor element which is capable of being elastically and at least indirectly pressed against the outer surface of the hollow body by an elastic endorsing element and capable of stretching due to the deformation of the hollow body due to frictional contact therewith. The endorsing element is combined with the sensor element and/or at least a part of the housing into one piece, whereby manufacture and adjustment of the transducer device are simplified.