摘要:
This interface connection through a hole (2) in a high-temperature-resistant and vacuum-proof insulating part (1), particularly of ceramic, glass, or a single crystal, consists of a metallic lead (4, 17) inserted into the hole (2) and having a coefficient of thermal expansion less than that of the insulating part (1), wherein at least one end of the lead, if it is flush with at least one surface of the insulating part, is covered with active brazing material which high-vacuum-seals it to the insulating part, or, if it projects beyond at least one surface of the insulating part, is high-vacuum-sealed to the insulating part by means of ring-shaped active brazing material (5'), since in the liquid phase, the active brazing material moves into the gap between the wall of the hole (2) and the lead (4, 17) due to capillary action. Thus, the available materials (insulating material, metals having a smaller coefficient of thermal expansion than the insulating part, active brazing materials) can be used in a different and novel manner such that the use of a lead covered with active brazing material can be dispensed with.
摘要:
The method for forming rings of uniform thickness from an active brazing alloy by melt-spinning the liquid alloy has the following steps: The alloy is liquefied in a crucible having a lateral opening whose height is approximately equal to the width of the ring material; the liquid alloy is forced out of the crucible onto the side surface of a metal drum of high thermal conductivity at a radial distance from the drum center approximately equal to the ring diameter, said metal drum rotating at a high circumferential velocity at a distance from the crucible approximately equal to the ring thickness; after an,,,approximately quarter to three-quarter turn of the active brazing alloy solidified on the metal drum into ring material, the latter is lifted off the metal drum by a mechanical deflector or a gas stream blown onto it in a direction opposite to the direction of rotation of the metal drum, and guided past the crucible; the ring helix being formed is guided around a lateral, coaxial extension of the metal drum which is located on one side of the crucible, serves as a winding mandrel, and has an end flange and a diameter slightly smaller than the inner diameter of the rings, and from the ring helix, the rings are cut off.
摘要:
The invention discloses a level measuring device which can be made up from components. It comprises a sonic or ultrasonic transducer which is arranged in a first housing and forms a self-contained functional unit; the electrical circuit arranged in a further separate housing forms a second functional unit. The functional units are so constructed that they can be assembled from the various components to a complete level measuring device in accordance with the required use conditions by arrangement of a steel plate above the sonic or ultrasonic transducer, or by potting with a commercially usual potting composition, or the selection of two different similar housings for receiving the sonic or ultrasonic transducer or the arrangement of selectively different but dimensionally identical sonic or ultrasonic transducers, and the selective mounting by means of a loose flange on a container, or by means of a suspension bracket in the interior thereof or above a drain.
摘要:
This pressure gage has a housing (b 10) with a first connection (1) for applying a first pressure (p1), an interior space (11) for receiving, mounting, and sealing a sensing element (3..), a wall (12) enclosing the interior space and having a channel (41) therein for guiding reference air or a second pressure (p2), and a cover (5). The sensing element (3..) comprises a diaphragm (31), to the outer side of which the first pressure (p1) is applied, and a substrate (32) having an opening (33) through which pressure is applied to the inner side of the diaphragm (31). The cover (5) has at least one feedthrough bushing (51) for electric leads (52) to the sensing element, means for sealing the interior space (11) from the environment of the pressure gage, a channel extension (42) extending the channel (41) in the wall (12) to an opening in the cover, and an inset which is sealed in the opening of the cover and which either is solid (inset 61) or has a connecting channel (43) between the channel extension (42) and a lengthening part (34) extending from the inner plane of the cover (5) to the opening (33) in the substrate (32) of the sensing element (inset 62) or is designed as a second connection (2) for applying the second pressure (p2), said second connection closing the channel extension (42) (inset 63). This construction serves to provide a pressure gage which is modifiable for use as either an absolute pressure or reference pressure or differential pressure gage and requires a minimum number of different parts adapted to the respective applications, and wherein one of the pressure connections can be fitted in one of the two main surfaces of the pressure gage.
摘要:
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.
摘要:
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. Alternatively, the measured value may also be derived from the first moment of the cross power density spectrum of the two signals because said moment is mathematically equivalent to the gradient of the time cross correlation function of the two signals for the time displacement zero.
摘要:
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. Parallel to the signal processing path for generating the envelope signal, in the evaluating circuit a frequency detection of the echo signals is carried out by which echo signals having the transmission frequency of the sonic or ultrasonic pulses are determined. In dependence upon the result of the frequency detection the signal processing path is opened only for the echo signals having a frequency corresponding to the transmission frequency. As a result all the reception signals having a frequency not corresponding to the transmission frequency are excluded from the digitizing and further processing. Due to the Doppler frequency shift these include all the reception signals which are caused by reflections at moving obstacles. On the other hand, all reception signals having a frequency identical to the transmission frequency are passed on unchanged for the digitizing and further signal processing.
摘要:
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. The value of the moisture-dependent electrical quantity measured on the transition of the periodic time variations to a monotonic variation is then used as the reference or desired value which is maintained by the control of the temperature of the sensor surface. Furthermore, the control parameters for controlling the moisture-dependent electrical quantity are continuously corrected on the basis of an oscillation analysis.
摘要:
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. Each delay circuit is formed by a write-read memory into the memory cells of which the consecutive bits of the binary signal to be delayed are written at the sampling rate under consecutive write memory addresses and out of the memory cells of which the stored bits are read at the sampling rate under consecutive read memory addresses differing from the write memory addresses by an adjustable address difference. Furthermore, the digital signal processing unit comprises two correlation units, each of which receives a delayed binary signal, an undelayed binary signal and a derivative binary signal corresponding to the derivative of the undelayed binary signal. Each correlation unit counts the sampling periods which are contained in an averaging time interval and in which a quantity calculated from the binary signals supplied assumes a positive numerical value or a negative numerical value. A computing and control circuit calculates from the two counts estimated values of correlation coefficients and their derivatives and controls the adjustable address difference in each delay circuit in dependence upon said estimated values so that the delay time is kept equal to the offset time.
摘要:
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. The sonic beam shaper results in the effect that the flexural oscillator plate radiates only soundwaves of equal phase while the soundwave of opposite phase thereto are suppressed by the soundwave barriers.