Abstract: This rugged, temperature-shock-insensitive, and low-cost pressure sensor (1) has a diaphragm (2) and a substrate (3) which are alumina-ceramic parts, preferably with a purity of 96%, are joined together in a defined spaced relationship and parallel to each other by means of an intermediate layer, forming a, preferably closed, chamber, and have flat inner surfaces which are provided with at least one conductive layer for forming at least one capacitor and are electrically connected to the respective rear side of the diaphragm or substrate via through-hole coatings. For the conductive layers (6, 7, 8), the through-hole coatings (12, 13, 14), and the intermediate layer (5), use is made of a conductive paste or a resistive paste with a sheet resistivity not higher than 1 ohm/square, which are applied using silk-screening techniques.

Abstract: A capacitive difference sensor includes two sensor electrodes, each of which lies opposite a transmitting electrode fed by an electrical AC voltage source. A circuit arrangment connected to the two sensor electrodes for signal recovery generates a differential signal which corresponds to the difference between the displacement currents induced in the two sensor electrodes. The circuit arrangement includes a series resonance circuit comprising a coil and a capacitor, the resonance frequency of the series resonance circuit corresponding to the frequency of the AC voltage source. The two sensor electrodes are coupled via a transformer in opposite senses to the series resonance circuit and the differential signal is tapped off at the tap of the series resistance circuit formed by the connecting point between the coil and the capacitor.

Abstract: The circuit arrangement for self-excitation of a mechanical oscillation system to natural resonant oscillations includes an electromechanical transducer system which is arranged in the feedback circuit of an electronic amplifier circuit so that it is stimulated by the output AC voltage of the amplifier circuit to mechanical oscillations and furnishes an AC voltage with the frequency of the mechanical oscillations to the input of the amplifier circuit. The amplifier circuit has a non-linear gain characteristic which at small values of the input signal gives a greater amplification than at lower values of the input signal. As a result a reliable oscillation start is ensured even under unfavorable operating conditions while on the other hand the danger of erroneous indications of the oscillation state, for example due to external vibrations, is reduced.

Abstract: The pressure sensor comprises a base body and diaphragm which are assembled at a defined distance apart parallel to each other to form a chamber, at least one of the two assembled parts consisting of ceramic, glass, metal or a monocrystalline material. In dependence upon the external pressure acting on the pressure sensor the distance between said parts and thus the capacitance between two electrodes carried by said parts changes. The base body and the diaphragm are firmly connected together by a shaped part of metal serving at the same time as spacer. If at least one of the two parts consists of ceramic, glass, metal or a monocrystalline material, the two joined parts can be soldered together by a shaped part of active solder. If the two assembled parts consist of oxide ceramic or sapphire they can be connected together by the direct copper bonding method. In this case the shaped part consists of copper which is connected to the two parts by a eutectic melt forming at the surface.

Abstract: The arrangement for contactless measurement of the volume flow or mass flow of a moving medium comprises two transducers which furnish electrical signals into which inhomogeneities of the moving medium enter depending on their spatial position in accordance with different spatial weighting functions. The detecting regions of the two transducers are offset with respect to each other in the direction of movement of the medium but partially overlap in such a manner that the gradient of the spatial cross correlation function for the spatial displacement zero is different from the zero vector. A correlator forms the time cross correlation function of the two signals and an evaluation circuit derives the measured value for the volume flow or mass flow of the moving medium from the gradient of the time cross correlation function for the time displacement zero.

Abstract: The filling level meter for measuring the filling level in a container includes a transmitting and a receiving arrangement which directs sonic or ultrasonic pulses onto the filling material surface and receives the backscattered pulses reflected by the filling material surface and converts them to electrical reception signals. Connected to the transmitting and receiving arrangement is an evaluating circuit which in a signal processing path generates an envelope signal corresponding to the envelope of the reception signals, digitizes sampled values of the envelope signal, stores in a memory the digitized sampled values for creating a distance-dependent or travel-time-dependent amplitude profile of the measurement distance and evaluates the amplitude profile for determining the travel time of the most probable useful echo signal.

Abstract: An arrangement for generating mean-value-free binary signals includes a binarizing circuit which receives an analog signal to be binarized and binarizes said signal with respect to a binarizing threshold. Connected to the output of the binarizing circuit is a closed-loop control circuit which includes a differential integrator which receives at the one input the binary signal from the output of the binarizing circuit. Applied to the second input of the differential integrator is a desired value signal which corresponds to the mean value between the two signal levels of the binary signal. The differential integrator integrates the deviation between the binary signal and the desired value signal and furnishes a signal corresponding to the integrated deviation. By the signal corresponding to the integrated deviation the position of the analog signal relatively to the binarizing threshold is shifted in a sense such that the mean value of the deviation is regulated to zero.

Abstract: A dew-point sensor for a dew-point measuring device for measuring the water vapor dew point in gases comprises a sensor surface which is exposed to the gas to be measured and on which on cooling to the dew-point temperature water vapor condenses. Mounted on the sensor surface are two electrode structures which comprise electrode portions which are arranged a uniform interval parallel to each other and which are covered with a moisture-insensitive insulating layer. The reaching of the dew-point temperature is determined by measuring the impedance or capacitance between the two electrode structures. The distance between the electrode portions, arranged parallel to each other, of the two electrode structures is of the order of magnitude of the diameter of the largest condensation droplet forming on reaching the dew-point temperature, or smaller than said diameter, and the thickness of the insulating layer is small compared with the distance between the electrode portions.

Abstract: For measuring the water vapor dew point in gases, a moisture-dependent electrical quantity of a sensor surface suitable for indicating formation of dew droplets is held by temperature control at a desired value corresponding to a stable dew mass. The temperature of the sensor surface corresponding to the desired value of the moisture-dependent electrical quantity is measured as dew point temperature. For compensating the influence of soiling, from time to time the desired value of the moisture-dependent electrical quantity is set in that the temperature of the sensor surface is lowered from a value lying above the dew point temperature and a periodic time temperature variation superimposed on the lowering. If the sensor surface is soiled, periodic time variations of the moisture-dependent electrical quantity occur at the same time but they become a monotonic variation when the dew point temperature is reached.

Abstract: Illustrated and described is an arrangement for leading a cable into a housing, preferably a cylindrical housing, for electrical or electronic devices. The housing is provided with a cylindrical housing part made detachably for connection of the connection cable. The housing part is divided into two parts, the lead-in sleeve 4 and a cap 3 covering the electrical connection elements. The cap 3 is connected by means of a connection part 10 to the housing 2 in the interior of which the electronic components are accommodated. The cap 3 is supported by axial portions of the connection part 10 and withdrawable from the latter in axial direction. The arresting is done by means of a spring element 21 which engages into a groove 22 of the connection part 10. Further grooves 26 which are arranged at the periphery of the inner wall 19 of the cap 3 and into which a right parallelepipedic protrusion 27 engages prevent turning of the cap 3 with respect to the housing 2.

Abstract: The invention relates to an arrangement for processing the output signals of a resistance bridge supplied with a DC voltage or a direct current with periodically reversed polarity. The arrangement further comprises a clock generator furnishing a clock signal controlling said reversal. The output signal of the resistance bridge is amplified in a bridge amplifier and supplied to a voltage-frequency converter with signal and reference inputs. The output frequency of said voltage-frequency converter is the output signal of the arrangement. The instantaneous bridge supply is used as reference for the voltage-frequency converter and the reversal of the polarity of the bridge supply is synchronized with the output frequency. The measurement of the output frequency in the following evaluating units takes place in such a manner that the mean value is formed over a whole number of reversal clock periods.

Abstract: A filling level measuring device for measuring the filling level of explosive media in a container is provided. The device includes a sonic or ultrasonic transducer and a mounting flange for mounting the filling level measuring device on the container. The separation necessary between the explosive media within the container and the electrical operating means of the filling level measuring device is effected by a planar homogeneous metallic surface of the mounting flange which faces the container interior and which includes a diaphragm of the sonic or ultrasonic transducer. To form the diaphragm in the mounting flange on its side remote from the container interior, the mounting flange is formed to include a cylindrical recess whose axis of symmetry coincides with that of the mounting flange. The sonic or ultrasonic transducer is disposed substantially within the recess formed in the mounting flange.

Abstract: The circuit arrangement is used for capacitance or admittance measurement by the principle of apparent current measurement in that to the capacitance or admittance to be measured an AC voltage of fixed magnitude and fixed frequency is applied and the AC current flowing through the capacitance or admittance is used as a measure of the measured value. The test object whose capacitance or admittance is to be measured lies in the emitter circuit of a transistor connected as voltage follower, to the base electrode of which the AC voltage is applied. The emitter terminal of the transistor connected to the test object is connected to the corresponding pole of the operating voltage source via an adjustable current source. The collector connection of the transistor is connected via an impedance of high resistance for alternating current to the other pole of the operating voltage source.

Abstract: The measuring circuit is used to measure the resistance ratio .DELTA.R/R in a resistance half-bridge comprising two series-connected resistors, of which the one resistor has the resistance R+.DELTA.R and the other resistor the resistance R-.DELTA.R. The two resistances are traversed by the same current which generates a voltage drop at each resistor. By an integrating SC amplifier in successive sampling cycles difference voltages which are proportional to the difference between the voltage drops at the two resistors are integrated to give an integration voltage. Every time the integration voltage exceeds an upper threshold value or drops below a lower threshold value in a compensation cycle a compensation voltage directed oppositely to the difference voltage is superimposed on the integration voltage and is proportional to the sum of the voltage drops at the two resistors. As a measure of the resistance ratio .DELTA.

Abstract: A digital correlator for determining the offset time between two random signals offset in time with respect to each other includes an analog signal processing arrangement and a digital signal processing unit. The analog signal processing arrangement generates by binarizing and periodic sampling of the random signals and their derivatives binary signals, each of which represents the polarity of one of the random signals or the derivative of a random signal at the sampling instants. The digital signal processing unit includes two delay circuits, each of which imparts to one of the binary signals a delay of an adjustable multiple of the sampling period.

Abstract: In a measuring system, a measuring signal is transmitted on a two-wire line by varying the DC supply current which is transmitted on the same two-wire line. In addition, binary-coded information signals are transmitted via the same two-wire line, each bit of the one binary value being represented by a group of a predetermined number of consecutive periods of a periodic signal, and each bit of the other binary value being represented by the absence of the same number of consecutive periods of the periodic signal. On reception, received periods of the periodic signals are counted in a first counting direction and missing periods are counted in the opposite counting direction between two limit counts. Reception of the one binary value is indicated when the first limit count is reached, and reception of the other binary value is indicated when the second limit count is reached.

Abstract: The acoustic transducer system includes an electroacoustic transducer and a flexural oscillator plate which is coupled to the electroacoustic transducer. The flexural oscillator plate is so constructed that at the system operating frequency it is stimulated to flexural oscillations of a higher order at which on the flexural oscillator plate node lines form between which antinode zones oscillating alternately in opposite phase lie. To influence the sound radiation of the flexural oscillator plate a sonic beam shaper is provided. The sonic beam shaper has soundwave barriers which are impermeable for soundwaves and which lie spaced from the flexural oscillator plate and acoustically decoupled therefrom in front of first antinode zones oscillating in equal phase with each other, and soundwave-permeable regions which lie between the soundwave barriers in front of the remaining second antinode zones oscillating in opposite phase to the first antinode zones.

Abstract: The arrangement includes a capacitive probe comprising pairs of sensor electrodes, arranged in a pseudo-random sequence, with which a common transmitting electrode is associated. The transmitting electrode is fed by an electrical voltage source and to the sensor electrodes of each pair an electrode circuit is connected which generates an output signal which corresponds to the difference of the displacement currents induced in the sensor electrodes. The electronic circuit is constructed such that it maintains the sensor electrodes at any time at a virtual ground potential. For this purpose each sensor electrode may be connected to the inverting input of an operational amplifier whose non-inverting input lies at the potential at which the sensor electrodes are to be held with respect to the supply voltage. The sensed signal is used in a correlative measurement of speed or travel time.

Abstract: A bulk flow meter having an inclined baffle plate disposed within a conveying space in the path of a bulk material to be measured is provided. The meter includes a measuring chamber that is separated from the conveying space by a partition. The baffle plate is carried by a baffle plate support which is horizontally movable under the impact of the bulk material and which includes a rod-shaped connecting member that extends through an opening in the partition. A dust protector is provided for preventing dirt and dust from entering the measuring chamber from the conveying space. The dust protector includes a rigid tube that surrounds a portion of the length of the rod-shaped connecting member on the baffle-side of the partition. Flexible diaphragms are provided for connecting the rigid tube to the partition and to the rod-shaped connecting member.

Abstract: The bulk flow meter comprises a baffle plate which is arranged inclined in the fall path of the bulk material to be measured and is carried by a rigid support which is mounted displaceably in the direction of a horizontal axis on at least two spring systems which are spaced apart from each other and secured on the one hand to the baffle plate support and on the other hand to the frame, each spring system having at least one pair of spring members arranged opposite each other on either side of the baffle plate support. Each spring member is formed by a corrugated diaphragm section with vertically extending corrugations. The corrugated diaphragms provide a mounting of the baffle plate support with high transverse stability so that it is possible to arrange the baffle plate without modifying the suspension optionally in the longitudinal direction of the baffle plate support or in the transverse direction laterally adjacent the baffle plate support.