Abstract: Described herein are a capacitive pressure detector, with an electrically conductive substrate (1), an electrically conductive, plate-like member (3) disposed at a distance from the substrate, and an electrically insulating layer (2') hermetically bonding together the substrate (1) and the member (3) such that a capacitor chamber is formed between the substrate (1) and the member (3), as well as a method for manufacturing same. The method comprises machining at least one recess (5) into one side of the substrate (1), applying a layer (2) of electrically insulating material in molten state onto the machined side of the substrate (1) such that the layer (2) covers the machined side of the substrate, allowing the layer (2) to harden, remowing material out of the surface of the structure in this way produced for obtaining a substantially plane surface with at least one conductive mesa portion (6) of the substrate (1) surrounded by at least one insulating layer portion (2').

Abstract: A capacitive pressure detector, comprising a plate-shaped base (13), a stationary capacitor plate (14) disposed on the base (13), an aneroid capsule (6) arranged in connection with the base (13) and proviced with an area (8) with a mobile capacitor plate facing the stationary capacitor plate (14) and changing its distance from the stationary capacitor disc (14) by the effect of pressure. On the plate-shaped base (13), a silicon plate (5) is disposed, into which a membrane-like middle portion (8) functioning as the mobile capacitor plate has been worked. On the silicon plate (5), a preferably plate-shaped cover structure (12) is hermetically disposed so that a basin space (6) of the aneroid capsule is formed between the cover structure (12) and said middle portion (8).

Abstract: A capacitive pressure detector, which comprises a support plate (5, 6; 19), a stationary capacitor plate (4; 7) disposed on the support plate, (5, 6; 19), and a silicon plate (2; 13) disposed on the support plate (5, 6; 19) so that it surrounds the stationary capacitor plate (4; 7), the middle portion of the silicon plate having been made thinner so that it forms membrane-like structure (3; 16) acting as a mobile capacitor plate. The support plate consists of a silicon layer (6; 21) and of a glass layer (5; 20) attached onto said silicon layer and placed against the silicon plate (2; 13), said glass layer being essentially thinner than the silicon layer. Hence, in the combination plate (5, 6; 20, 21) in this way obtained, owing to the elasticity coefficients and thermal expansion coefficients of the different layers (5 and 6; 20 and 21), the difference in thermal expansion between the combination plate (5, 6; 20, 21) and the silicon membrane (3; 16) is essentially reduced.

Abstract: The present publication describes a capacitive humidity sensor and a method for the manufacture of same. The sensor comprises a substrate (1), first (5) and second bottom electrodes (4), which have been fitted close to each other on the substrate (1), an active layer (7), which fills the area between the first (5) and the second bottom electrodes (4) on the substrate (1) and extends to above the top face of the second electrode (4). According to the invention, the sensor further consists of structures (6) connected to the top face of the first electrode (5), made of a conductive material, and being beam-shaped with an upwardly widening section and being placed side by side, the said structures (6) limiting portions (7) of the active layer between themselves from two sides, and a narrow slot (26) being provided between the top faces of the said structures. Owing to its construction, the sensor is not sensitive to touching.

Abstract: Apparatus for attaching a sounding balloon by its filling tube to a device which is adapted to be connected to a radiosonde by a flexible connecting element includes an attachment member in which an aperture is formed and a fixing member adapted to be fitted in locking position on the attachment member so that at least a portion thereof extends through the aperture. The fixing member includes at least one wedge-shaped portion which extends through the aperture of the attachment member when the fixing member is fitted into locking position to urge the filling tube of the sounding balloon against the marginal edge of the aperture to fix the filling tube and, therefore, the sounding balloon to the attachment member. The attachment member preferably is integral with a plate body which widens in a downward direction and which constitutes a device for releasing the flexible connecting element between the radiosonde and the sounding balloon in a controlled manner.

Abstract: Bobbin apparatus for releasing a connecting filament between a radiosonde and the sonde balloon in a controlled manner during the ascent thereof includes a longitudinally extending member adapted to be affixed to the balloon around which the filament is wound and having a transverse dimension which increases in the longitudinal direction from a narrow upper end to a wide lower end thereof. The filament will unwind from the bobbin member during ascent of the balloon causing the bobbin member to periodically oscillate in a manner such that the filament will unwind without fouling and at an appropriate rate.

Abstract: A piezoelectric sensor consists of material for transmitting elastic waves and has a surface subjected to the condensation and presence of dew and liquid to be detected. A wave producing device includes a transmitter for producing an acoustic surface wave on the surface in conjunction with piezoelectric phenomena of the sensor. A detector includes a receiver for receiving the wave after transmission thereof across the surface. The wave is variably attenuated in transmission between the transmitter and receiver in accordance with dew or liquid on the surface. A measuring device measures the attenuation of the detected wave and thereby indicates the dew point or presence of liquid on the surface.

Abstract: A detecting transmitter device installed in operative proximity with a surface to be observed includes an ultrasonic waveguide installed in such surface. Electronic equipment electrically connected to the ultrasonic waveguide transmits ultrasonic waves to the waveguide. The ultrasonic waves proceed in the waveguide. The equipment also receives the ultrasonic waves from the waveguide. The degree of attenuation of the waves in the waveguide depend upon the difference in viscosity and other mechanical properties of water and ice, whereby the detecting transmitter device and the electronic equipment detect freezing of the surface by attenuation of the waves in the waveguide.

Abstract: A capacitance to be measured is connected between the input and output of an inverting amplifier. A bistable circuit has an input connected to the output of the inverting amplifier and an output impedance inversely proportional to the capacitance to be measured. A resistive feedback is connected from the output of the bistable circuit to the input of the inverting amplifier.

Abstract: The output of each of a plurality of CMOS inverting amplifiers is connected to a corresponding one of a plurality of impedances to be measured. A stepping circuit is connected to the inputs of the amplifiers. A voltage supply is connected to the amplifiers and provides a signal to be measured which is directed via a corresponding one of the amplifiers to an impedance measuring circuit connected to the impedances to be measured in common. The impedance measuring circuit produces an output impedance proportional to the impedances to be measured.

Abstract: A capsule for use in aneroid pressure gauges comprising a pair of membranes sealed to each other along peripherally extending side edge regions to define a sealed, interior space therebetween. One of the membranes is formed having a centrally located charge retaining region. A capacitor plate is fixed to the other membrane and is disposed within the sealed interior space in opposed relationship to the charge retaining region. The means by which the capacitor plate is fastened to its respective membrane is electrically conductive and extends through the membrane while being electrically insulated therefrom. Changes in pressure are measured by measuring the changes in the capacitance between the capacitor plate and charge retaining region, the latter changes being effected by the changes in the distance between the membranes resulting from pressure fluctuations. The aneroid capsule is particularly suited for use in connection with an aneroid pressure gauge utilized in radiosondes.

Abstract: A capacitive signal dependent upon a quantity being measured is produced by capacitive sensors of a radiosonde. An oscillator in the radiosonde has an output frequency, controlled by the capacitive signal, in the order of 1 to 10 MHz. The output frequency of the oscillator is divided by a factor of 2.sup.7. A high frequency transmitter in the radiosonde is frequency modulated by a frequencyf.sub.M1 =f.sub.M0 /dwherein f.sub.M1 is the output frequency of the divider and f.sub.M0 is the input frequency of the divider.

Abstract: A capacitive humidity transducer wherein an electrically non-conductive base carries at least a pair of electrically conductive coatings which are spaced from each other. A dielectric film which is active with respect to water absorption is also carried by the base and covers at least portions of the coatings, the dielectric film having a dielectric constant the value of which varies as a function of the extent to which water has been absorbed by the dielectric film. An outer electrically conductive, water-permeable layer is carried by the dielectric film with this film being situated at least in part between the coatings and the layer while the latter because of its water permeability permits moisture in the atmosphere to reach the dielectric film. The dielectric film maintains the outer layer permanently out of contact with at least one of the coatings, so that it is possible to measure between these coatings a capacitance which will be indicative of atmospheric humidity.