Abstract: The arrangement for contactless measurement of the velocity 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 velocity of the moving medium from the gradient of the time cross correlation function for the time displacement zero.

Abstract: An ultrasonic echo sounding apparatus disposed at a measuring location transmits ultrasonic pulses in successive transmission periods. The echo pulses received after reflection at a target are converted to electrical envelope signals which represent the envelope curves of the echo pulses. The envelope signals are transmitted via a connecting line to an evaluation apparatus disposed at an evaluation station remote from the measuring location. In the evaluation apparatus the envelope signals are evaluated for determining the target distance from the travel time of the ultrasonic pulses. The transmission of envelope signals results in the advantage that the information contained in the pulse shape of the echo pulses is available in the evaluation station, although it is not necessary to transmit signals having the high frequency of the ultrasonic pulses via the connecting line.

Abstract: The sonic or ultrasonic distance measuring device used for example to measure the filling level in a container comprises an electroacoustic transducer which operates alternately as transmission transducer for the transmission of sonic or ultrasonic pulses and as reception transducer for the reception of the reflected echo pulses. Connected to the transducer is a signal processing circuit which includes an amplifier with controllable gain and a threshold value discriminator. A gain control circuit controls the gain of the amplifier during a predetermined period after the start of each transmission pulse in accordance with a stored function which is fixed in accordance with the dying-down behaviour of the transducer so that the electrical signals originating from the dying-down of the transducer after amplification are smaller than the threshold value of the threshold value discriminator but are as close as possible to said threshold value.

Abstract: A pressure sensor has a housing in which at least two diaphragms are secured in such a manner that they include a volume which is filled with a hydraulic fluid. The incompressible hydraulic fluid serves to transmit pressure between the diaphragms. For introducing the hydraulic fluid one diaphragm is provided with an opening. A narrow tube is connected in fluid-tight manner to the edge of the opening. The hydraulic fluid is introduced through the initially still open end of the narrow tube. After the filling with hydraulic fluid the open end of the narrow tube is sealed in fluid-tight manner, for example by squeezing. The narrow tube can serve at the same time a force-transmitting or travel-transmitting member which connects the diaphragm to a force or travel sensor.

Abstract: A dew-point measuring instrument has a capacitive dew-point sensor 1 which is cooled by a cooling device 17 to the dew-point temperature measured by a temperature sensor 8. A phase measuring circuit 14 measures the phase angle of the impedance of the capacitive dew-point sensor 1. The measured phase angle is used as a gauge for the contamination of the dew-point sensor 1.

Abstract: A plastic scintillation detector (14) generates on the basis of ionizing radiation coming from a radiation source (16) light flashes which are converted by a photoelectric transducer (20), for example a photoelectron multiplier, to electrical output pulses. An evaluation circuit (22) counts the output pulses as a measure of the radiation intensity. For automatic stabilization of the scintillation detector a light source (24) is controlled by a driving circuit (26) in such a manner that it transmits light pulses whose intensity is modulated in accordance with a predetermined periodic function, for example a sawtooth function. The modulated light pulses are also intercepted by the photoelectric transducer (20) and converted by the latter into electrical reference pulses. A monitoring circuit (28) determines in each modulation period the number of reference pulses whose amplitude exceeds a predetermined reference threshold value lying in the modulation interval.

Abstract: The sensor (20) is intended for the detection of random signals, suitable for correlative signal processing, originating from a process in motion relative to the sensor, for example a flow passing through a pipeline (1). Signals of this nature are used, in particular, for the measurement of velocity or running time. The sensor (20) is subdivided into several sensor segments (21, 22, 23, 24) in order to increase sensitivity for a given spatial frequency filter effect. In the case of a capacitive sensor, each sensor segment consists of two electrodes encompassing the pipeline (1). The sensor segments (21, 22, 23, 24) are arranged along the direction of motion according to a coding selected on the basis of the desired spatial frequency filter effect, with the introduction of gaps (25, 25, 27) which are insensitive to the characterizing parameter of the process in motion.

Abstract: A thin-film humidity sensor for measuring the absolute humidity having a base electrode, a moisture-sensitive dielectric layer and a top electrode is formed at the end face of an electrically insulating bushing body by the thin-film technique. The connecting conductors are led through the bushing body and terminate in contact areas which are ground plane and polished together with the end face of the bushing body. The metal layers forming the electrodes are so shaped on application, preferably by means of perforated masks, that they each cover the contact area of the associated connecting conductor and are electrically connected thereto. The bushing body is inserted into a sleeve of a highly alloyed nickel-molybdenum compound and connected thereto in pressure-resistant manner.

Abstract: The device for determining and/or monitoring a predetermined filling level in a container has two oscillatory rods secured with spacing adjacent one another on a diaphragm the edge of which is connected to a screw-in part. By means of the screw-in part the device is so secured in a screw-threaded aperture of the container wall at the height of the filling level to be detected that the oscillatory rods project into the container. At the side of the diaphragm remote from the oscillatory rods a bridging member is held spaced from the diaphragm by flexurally elastic rod-shaped supports. Each of the rod shaped supports is rigidly connected at one end to an oscillatory rod. Between the bridging member and the diaphragm there is held, with preloading of the diaphragm, a transducer column comprising in a stack a piezoelectric excitation transducer and a piezoelectric reception transducer.

Abstract: A sensor for capacitively measuring the level of material in a container where the sensor extends through an opening in the container and is connected to measuring circuitry. The sensor includes an electrically conductive, tubular member aligned with the opening. An elongated electrically conductive member is in electrical contact with the circuitry and projects through the container opening and the tubular member such that a space is established between the elongated conductive member and the tubular member so that they are electrically insulated from one another. The space is sealed to prevent entry of moisture therein.

Abstract: The resistance thermometer comprises a temperature dependent measuring resistor (10) and a measuring circuit (11) for measuring the voltage drop at the measuring resistor which is produced by a current (I) flowing across the measuring resistor (10). The measuring resistor (10) lies in the feedback circuit of an operational amplifier (A.sub.1) whose inverting input is applied via a resistor (21) to a constant reference voltage (E). To linearize the characteristic of the measuring circuit a voltage (k.U.sub.T) is applied to the non-inverting input of the operational amplifier (A.sub.1), which voltage is in a predetermined ratio (k) to the output voltage (U.sub.T) of the measuring circuit (11).

Abstract: The capacitive sensor has a tubular plastic housing (10) which is closed at the front end and which consists of a tubular body (11) and a cup-shaped cap (12). In the cap (12) a pot-shaped sensor electrode (13) and a tubular guard electrode (14) are disposed. The tubular body (11) contains an electronic circuit (20) and a tubular shield electrode (15). The tubular electrodes (14, 15) are impact-resistant metal tubes, preferably of steel, and the pot-shaped sensor electrode (13) is an impact-resistant metal member, likewise preferably of steel. Between the electrodes (13, 14, 15) elastically deformable spacer members (16, 17) are inserted. For assembling the sensor the sensor electrode (13) and the guard electrode (14) with the spacer (16) disposed therebetween are arranged in the cap, and the shield electrode (15) is introduced from the front into the body (11) up to a stop (24) disposed in the body (11).

Abstract: A deflecting spring for distance or force measurement, particularly suited for use in force or pressure gauges and made of an areal spring material is provided with a force introducing section (2), a clamping section (6), and an intermediate section (45) connected to the first two sections (2,6) by flexural webs (10-13) which are equipped with sensor elements serving to convert bending into electrical signals. The intermediate section comprises two part sections (4,5) disposed at either side of an axis of symmetry (S) of the deflecting spring and each connected by a first web (10,11) with the force introducing section and by a second web (12,13) with the clamping section (6). By virtue of this design of the deflecting spring the respective webs belonging to a part section each are deflected in opposite directions when the force introducing section (3) is bended so that also opposite output signals are generated by the sensor elements.

Abstract: A moisture sensor is manufactured by applying a thin layer of tantalum oxide to a moisture insensitive substrate and placing at least two electrodes on the tantalum oxide layer. The tantalum oxide layer comprises the oxide of a highly resistive low density tantalum where the tantalum in the layer applied to the substrate has a density of less than 15 g/cm.sup.3. The low density tantalum may be applied by cathode sputtering and the oxide may be formed by anodic oxidation.

Abstract: A thin-film humidity sensor for measuring the absolute humidity having a base electrode, a moisture-sensitive dielectric layer and a top electrode is formed at the end face of an electrically insulating bushing body by the thin-film technique. The connecting conductors are led through the bushing body and terminate in contact areas which are ground plane and polished together with the end face of the bushing body. The metal layers forming the electrodes are so shaped on application, preferably by means of perforated masks, that they each cover the contact area of the associated connecting conductor and are electrically connected thereto. The bushing body is inserted into a sleeve of a highly alloyed nickel-molybdenum compound and connected thereto in pressure-resistant manner.

Abstract: A moisture sensor comprises a moisture-sensitive layer formed from the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate. Between the substrate and the moisture-sensitive tantalum oxide layer there is a base electrode of an anodically oxidizable metal, preferably tantalum, of a density higher than the density of the low density tantalum from which the tantalum oxide layer is formed. A covering electrode partially covering the tantalum oxide layer has windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer. The inactive regions of the tantalum oxide layer disposed below the windows are removed to increase the rate of response.

Abstract: Disclosed is a capacitance level measuring device comprised of a container whose level is to be measured and a probe inserted into and spaced from the container. The capacitance between the probe and container varies in relation to the level in the container. A capacitance measuring circuit determines the capacitance between the probe and container and thus indicates the level in the container. The integrity of the probe is verified by constructing the probe so as to include it in a series circuit, as well as the capacitance measuring circuit, and a lack of continuity in the probe is indicative of questionable probe integrity. The question as to the probe's integrity would indicate a questionable level indication from the capacitance measuring circuit. Various probe constructions are also disclosed.

Abstract: A moisture sensor including a thin layer of tantalum oxide applied to a moisture insensitive substrate and at least two electrodes placed on the tantalum oxide layer spaced apart from each other wherein the tantalum oxide layer comprises the oxide of a highly resistive low density tantalum where the tantalum in the layer applied to the substrate has a density of less than 15 g/cm.sup.3.

Abstract: A method of measuring the bath level in a cool tubular mould utilized in a continuous casting process where a melt of metal to be cast is discharged from a container therefor into the mould via an immersion tube vertically extending into a bore through the mould to thereby establish the bath, there being an annular space between the immersion tube and the wall of the bore, and where the melt is soldified by the cooled mould and continuously withdrawn therefrom as a solidified bar.

Abstract: An arrangement for determining the level in a container includes a capacitive probe disposed in the container, a measuring transducer arranged in the vicinity of the container, and a remote evaluation apparatus. The measuring transducer produces a signal corresponding to the capacitance between the probe and the container. This signal, which is indicative of the level in the container, is transmitted from the transducer to the evaluation apparatus via a two-wire line, which also transmits the current supply DC voltage from the evaluation apparatus to the transducer. The transducer includes a switch for periodically switching from the probe capacitance to a test capacitance. The evaluation apparatus comprises a time control circuit which periodically varies or interrupts the DC voltage on the two-wire line, and the transducer includes a control circuit which responds to the voltage changes to actuate the switch.