Abstract: In pressure sensor systems based upon a micromachined silicon pressure sensor comprising a resonantly vibratable beam supported on a diaphragm, the beam is excited into resonant vibration by directing an optical excitation signal at the beam resonant frequency, via an optical fibre 26, onto a part of the sensor other than the beam, preferably the diaphragm. To detect the vibrations, the underside of the beam 16 and the adjacent upper surface of the diaphragm 18 are together arranged to define a Fabry-Perot cavity, and a continuous optical detection signal is directed at this cavity, also via the optical fibre 26. The optical detection signal is thus modulated at the vibration frequency of the beam 16 by the cavity, and the modulated signal is reflected back into the optical fibre 26.

Abstract: A unit which is useful in a measuring device such as a vibration rod transducer. The unit comprises supported diamond layers having an unsupported bridging diamond strip which is integrally formed with the supported diamond layers. The supported diamond layers may form part of a closed configuration such as a circle, square, rectangle or triangle. The diamond is preferably CVD diamond.

Abstract: The accelerometric sensor is of the type comprising a fixed mass, a mobile mass and two flectional vibrating beams each having ends that are linked to the masses. According to the invention, the masses and the beams consist of one single piece machined in a same plate of material of uniform thickness, e.g. in a piezoelectric material such as quartz. The single piece preferably comprises two second beams each having ends that are integral with the masses and placed on both sides of the vibratory beams. The flexural stiffness of the second beams is higher than that of the vibrating beams.

Abstract: An accelerometer comprising a monolithic crystalline substrate, the substrate comprising a support, a proof mass, and a force transducer. The proof mass is connected to the support by one or more proof mass flexures that permit the proof mass to rotate with respect to the support about a hinge axis. One end of the force transducer is connected to the support, and the other end is connected to the proof mass by a transducer flexure. The transducer flexure has a thickness substantially less than the thickness of the transducer, such that when the proof mass rotates, the transducer rotates with respect to the proof mass about a transducer axis that passes through the transducer flexure. Preferably, the transducer axis is offset from the hinge axis in a manner so as to cancel nonlinearities in the force transducer, and the length of the proof mass along the pendulous axis is less than half the length of the transducer.

Abstract: A tensioned bellows pressure transducer having a pressure chamber [40], an elastic vibrating member [50], an electromagnetic coil [60] a linkage [33], a rigid body [30], a body extension [35], and a pressure deformable member [22] defining in part a reference chamber [20]. In preferred embodiments, the pressure deformable member is a bellows. Bellows [22] is attached at bellows fixed end [23 to rigid body [30] and is deformable in response to a difference between a bellows internal reference pressure p.sub.0 and any pressure p.sub.1 external to bellows [22], such as in pressure chamber [40]. Elastic vibrating member [50] is connected at a first end to linkage [33]. Linkage [33] projects rigidly from an interior face of bellows free end [24] and vibrating member [50] is connected to linkage [33] at a distance d.sub.2 from free end [24], and is connected to body extension [35] at a distance d.sub.1 from free end [24], where d.sub.1 is less than d.sub.2.

Abstract: In a micromachined silicon pressure sensor comprising a resonantly vibratable beam supported on a diaphragm, the beam is indirectly excited into resonant vibration by directing an optical excitation signal at the beam resonant frequency onto a part of the sensor other than the beam, preferably the diaphragm. Preferably, the optical excitation signal is of a wavelength to which the sensor is fairly transparent, and is directed through the beam and diaphragm to be absorbed by a suitable coating on the underside of the diaphragm. The optical excitation signal produces local heating, and the resulting expansions and contractions at the beam resonant frequency propagate through the sensor structure to excite the beam into resonant vibration. Another optical signal is used to detect the frequency of vibration of the beam, and a positive feedback loop maintains the frequency of the excitation signal equal to the detected beam vibration frequency.

Abstract: A balance and an elastic, force reducing dynamometer. The dynamometer, is of the type having a plurality of plate springs and a laterally oscillating wire clamped between a pair of wire clamping heads which are shifted under load only in a direction parallel to the clamping heads. This result is achieved by mounting the wire clamping heads in approximately the center of the corresponding one of two plate springs with a pair of struts. In alternate embodiments of the invention, both struts which mount a clamping head may be straight, one strut may be straight and the other strut offset, or both struts may be offset. The elasticity of the struts and the ratios are variable and adjustable within wide limits.

Abstract: A device to measure the tension of the stringing of rackets used for playing tennis, squash, etc. which entails an end area to strike the said stringing and another adjacent area which includes a multiple diapason or tuning device. On striking the stringing, and depending on the tension of the strings, one tooth of the multiple diapason vibrates, thus providing a signal which can later be measured or digitalized to provide a measurement of the tension of the stringing.

Abstract: A strain gage assembly is secured between two initially longitudinal locations on the exterior of a flexible elongated member, such as a steel structural cable, or an electrical transmission cable, or a glass fiber optic communication cable, to thereafter upon the subsequent pre-stressing and/or the possible excessive straining of the cable, create an observable or transmittable reading of the excess tensile and torsional strain being sustained by the flexible elongated member. This assembly, in one embodiment, has an in line arrangement of a vibrating wire strain gage, the vibrating wire thereof secured to a calibrated coiled spring, in turn secured to an inner tube shaft, in turn telescopically fitted within an outer tube shaft, secured to the vibrating wire strain gage. Using two spaced securement means, this strain gage assembly is secured to the exterior of a flexible elongated member.

Abstract: The invention relates to a method and apparatus for automatic analysis for determining the size distribution of particles and their deviation from a desired shape and color. The method includes the collection of particle samples and the generation of a particle curtain in a monolayer form. It is formed by taking particles through a silo whose distance (a) to a vibrating plate positioned below has a length relative to the distance (b) between the outer edge of the plate and the center line of the silo that is large enough for the particles flowing out of the silo and down onto the plate and out over its edge to form an angle .alpha. with the horizontal plane. The angle .alpha. is 50-90% of the sliding angle of the particulate material. The particle curtain is lit up and the silhouette of the particles therein is recorded and analyzed and presented in at least one place.

Abstract: A method and device for measuring the string tension of a strung racket such as a tennis racket wherein a mechanical/electrical transmitter is attached to the membrane made from the racket strings mounted crosswise onto a frame and measures the frequency of the membrane. The membrane is induced to freely oscillate in an aperiodically (non-periodically) manner by a light stroke onto the frame or by dropping a ball onto the membrane. The measured frequency is proportional to the string tension which is indicated by a display.

Abstract: A monolithic resonator for a vibrating beam accelerometer is provided which comprises an outer structure including a mounting structure, a proof mass structure, a plurality of flexure beams extending between the mounting and proof mass structures; and an inner structure including first and second isolator masses, first and second isolator beams connected to one portion of the isolator masses, respectively, and a vibrating beam extending between other portions of the isolator masses. The monolithic resonator is non-planar in that the outer structure has a thickness greater than said inner structure.

Abstract: A force sensing device especially suitable for use in an accelerometer or a pressure transducer, depending upon its particular design. This device includes at least one and preferably two adjacent and parallel, elongated vibratable tines and means for vibrating the tines back and forth in a direction normal to their axes of elongation. These tines are supported for vibration by an arrangement including an array of interconnected links and mounting means adapted to be connected to an external member capable of applying a variable external force to the support arrangement along an axis normal to the axes of elongation of the tines. The support arrangement is configured so as to apply to the tines its own internal force in response to and varying with the external force in a way which causes the tines to vibrate at a frequency that varies with the magnitude of the internal force and therefore the external force.

Abstract: A vibration type force detector comprising: a string to which a force to be measured is applied in the direction in which the string is tensioned; a driver for causing the string to vibrate at its natural frequency and simultaneously producing a series of pulses at a frequency in synchronism with the vibration of the string; a gate to which the series of pulses are applied; a counter for counting the series of pulses that have passed through the gate; means for providing a gating time determined in accordance with the result of the counting of the counter; and a controller for controlling the gate in accordance with the gating time. The gating time providing means is so arranged that as the vibration frequency of the string increases, the gating time lengthens.

Abstract: An accelerometer fabricated by silicon etching techniques. A first suspended beam is formed having a first conductive portion, the beam being deflectable in response to an acceleration force. a second beam having second and third conductive portions is suspended over the first beam. Phased lock loop circuitry oscillates the second beam at resonance and provides an electrical signal proportional to the acceleration force.

Abstract: An inertial guidance accelerometer is formed as an integrated, monolithic, structure. Silicon micro-machining techniques are used to combine mechanical and electrical components of the device in a single crystal silicon wafer. The proof mass, flexible hinge, and resonator are formed by etching portions of a substrate, while the electrical circuits are monolithically integrated into the substrate using standard circuit integration techniques. The accelerometer includes a feedback control circuit for the resonator, as well as a digital-to-analog converter, for providing digital output signals indicative of the acceleration force applied to the device.

Abstract: A low-cost pendular non-serviced accelerometer comprises a base, a pendular seismic mass connected to the base by a hinged connection for pivotal movement of the seismic mass about an axis along a sense direction perpendicular to the hinged connection and a sensor connecting the seismic mass to the base. The sensor comprises at least two vibrating beams of piezo-electric material, each connected to the base at an end thereof and to the seismic mass at the other end thereof, and each provided with electrodes for vibrating the respective beam at a tuning frequency thereof. The beams are directed orthogonally to the sense axis and are located symmetrically with respect to the seismic mass on both sides of the hinged connection, whereby any acceleration along the sense axis creates tractive stresses in one beam and compression stresses in the other beam.

Abstract: A pressure transducer 10 is disclosed wherein a bellows 11 is expanded by an external pressure applied at pressure port 16. The force created by external pressure applied to bellows 11 is mechanically transferred to one end of a vibrating elastic member 14 by axial displacement of saddle 13. A change in external pressure is thereby read as a change in resonant frequency of elastic member 14.

Abstract: A method of monitoring the tension in a flexible drive belt (1) which passes around a plurality of pulleys (2, 3) includes the steps of causing a portion of the belt (1) when installed around the pulleys to vibrate at a natural frequency and detecting that frequency. In one arrangement the belt (1) is set into a vibrating motion by an impulse and the frequency of the transient vibrations measured. In another arrangement the belt (1) vibrated by a drive mechanism which receives a drive signal derived from the belt movement. Specific methods and apparatus for monitoring the tension are also applied to measuring the tension in elongate flexible members other than drive belts.

Abstract: Device for fastening a vibrating wire to a component of a meter. The device comprises a body having two prongs and two cylindrical, conical, prismatic or wedge-shaped retainers made of electrically insulating material. The retainers are in contact with the prongs on one side and, due to the clamping action of the prongs, hold the full width of the wire by friction on the other side, insulating it electrically.

Abstract: A vibrating beam force transducer that can be realized in a silicon micromachined device such as a micromachined accelerometer. The transducer includes a beam having a longitudinal axis, and a drive circuit electrically coupled to the beam for causing the beam to oscillate at a resonant frequency that is a function of a force applied along the longitudinal beam axis. The drive circuit provides an electrical current to the beam, and the beam, or a conductive portion thereof, conducts the current along a path that includes an axial component parallel to the longitudinal axis. A magnetic field is created intersecting the axial component, such that the electric current interacts with the magnetic field to produce a force that causes the beam to oscillate at the resonant frequency. In a preferred embodiment, the transducer has a double ended tuning fork configuration, and the current path extends along one beam and back along the other beam.

Abstract: An apparatus is provided for determining the natural frequencies of a longitudinally oscillating band excited by a transmitting oscillator, and whose oscillations are received by a receiving oscillator and evaluated. At least one of the exciting oscillator and the receiving oscillator is a sandwich oscillator having metal end masses. The oscillations are transmitted longitudinally along the pre-tensioned length of the band disposed between the transmitting oscillator and the receiving oscillator. An attachment device for attaching the band to the respective oscillators includes a roller which is spring-biased to rest in a groove formed in one face of each of the respective oscillators.

Abstract: A resonant bridge two-axis microaccelerometer is disclosed comprising polysilicon resonant bridges orthogonally attached to a silicon proof mass, such that the silicon proof mass is suspended by the resonant bridges. Acceleration in the plane of the substrate causes differential axial loads on the opposing microbridges in each pair, thereby shifting their resonant frequencies. The acceleration component aligned with a pair is measured by the difference in resonant frequencies.

Abstract: A dual vibrating beam force transducer having an electrostatic drive system. The transducer comprises a body having first and second generally parallel beams, coupled together at their ends. First and second electrodes are positioned adjacent to but not in contact with the respective beams. A drive circuit causes an oscillating voltage to be applied to the electrodes. The beams are thus subjected to electrostatic forces that cause the beams to oscillate in a vibration plane containing both beams. The mechanical resonance of the beams controls the oscillation frequency, such that the frequency is a function of a force exerted along the beams. An embodiment is also described in which the drive means is coupled directly to one of the beams.

Abstract: First and second Hall-effect proximity sensors are arranged in combination with a magnet so that when the magnet is moved under the influence of an accelerative force or the like the output of one sensor increases while the other decreases. The magnitude of the difference between the two outputs is indicative of the force while the effects of temperature on the individual signals mutually offset one and other.

Abstract: A vibrating wire strain meter has a steel proving ring across the bore of which extends a taut wire. The outer surface of the proving ring has sloping or tapered grooves extending axially along the entire length of the ring. A pair of diametrically opposed wedges sloping at the same angle as the grooves are used to wedge the proving ring in a borehole. The tapered grooves provide positive guiding of the wedges such that the device can be positioned accurately and repeatably in relation to the borehole wall. Preferably, the wire extends across a diameter which is perpendicular to the diameter on which the grooves and wedges are located. A novel tool for inserting and withdrawing the strain meter is also described.

Abstract: A force sensing device especially suitable for use in an accelerometer or a pressure transducer, depending upon its particular design. This device includes at least one and preferably two adjacent and parallel, elongated vibratable tines and means for vibrating the tines back and forth in a direction normal to their axes of elongation. These tines are supported for vibration by an arrangement including an array of interconnected links and mounting means adapted to be connected to an external member capable of applying a variable external force to the support arrangement along an axis normal to the axes of elongation of the tines. The support arrangement is configured so as to apply to the tines its own internal force in response to and varying with the external force in a way which causes the tines to vibrate at a frequency that varies with the magnitude of the internal force and therefore the external force.

Abstract: A user-programmable sensor system for generating an alarm signal upon detection of an alarm event is disclosed. The system is particularly suited for use in vehicle security systems. The system employs a three axes accelerometer as a shock/motion detector, and the transducer outputs are summed and the composite signal filtered to provide several channels, each covering a specific frequency or frequency band. The outputs of the channels are digitized and processed by a microprocessor. An event is characterized by seveal signal parameters with an alarm event triggered by the simultaneous occurrence of several predetermined conditions, and not just one condition. The limit values for the signal parameters which are required to qualify a shock/motion event as an alarm event may be readily programmed by the user at any time or place.

Abstract: A strain or pressure responsive transducer comprises a pair of elongate beam resonators arranged end to end and provided with a flexible coupling therebetween. The arrangement oscillates e.g. in a double see-saw or butterfly mode. The transducer is disposed on a diaphragm whereby strain may be transmitted to the oscillatory system. The frequency of oscillation is a function of this strain.

Abstract: An accelerometer is provided by a sample mass suspended in a central area of a support by pairs of resonating arms. One pair of arms lies on one axis through the sample mass. Another pair of arms lies on a second axis through the sample mass perpendicular to the one axis. Acceleration of the mass and support is detected by a measured change in resonant frequency of the arms of a pair. The measured change in resonant frequency is the magnitude of the acceleration and the axis along which the pair of arms lies provides the direction of the acceleration. Orthogonal components of acceleration are simultaneously measured by the pairs of arms lying on perpendicular axes. Electrostatic force-rebalance techniques and other known techniques for measuring acceleration in a direction perpendicular to the axes of the pairs of arms are readily incorporated to provide a third direction measurement of acceleration. The accelerometer is fabricated in a monolithic process which employs micromachining techniques.

Abstract: An accelerometer is provided comprising an inertial mass connected to a support by means of a hinge and a vibrating element whose ends are respectively fixed to the inertial mass and to the support. The hinge is disposed in the median plane of the vibrating element and the centers of gravity of the vibrating element and of the inertial mass are merged. The effects of internal thermal stresses, which vitiate the results, are considerably reduced.

Abstract: A force sensor comprising a resonator (10) having a frequency that varies with the force being measured. The resonator includes an oscillatory bar (101, 102) and a pair of anchor members (12, 103, 104) that are connected each to a corresponding end portion of the bar and which are adapted to apply the force having to be measured to the bar. The sensor further comprises a tube (16) that surrounds the resonator and which is rigidly secured by its end portions to the anchor members (12).

Abstract: A circuit (62, 64) for receiving a periodic input signal at frequency f, and for producing a pseudosinusoidal staircase output signal at a fundamental frequency f from which predetermined harmonics of the fundamental frequency are absent. Also provided are an oscillator in which such a circuit forms the drive circuit for a piezoelectric crystal, and an accelerometer in which such an oscillator is used as the force sensing means. In the accelerometer, the reaction force of a proof mass (40) is sensed by a resonator that comprises a drive circuit (44) for producing a drive signal and a piezoelectric crystal (42) connected between the proof mass and support (46). In response to the drive signal, the crystal undergoes mechanical vibration at a frequency f that varies with the force applied to the crystal. A resonator signal corresponding to the mechanical vibration is produced and input to drive circuit.

Abstract: A semiconductor vibration detecting structure formed on a semiconductor substrate and a method of manufacturing the same in which the curvature of the cantilever of the vibration detecting structure in the direction gradually deviating from the surface of the semiconductor substrate can be determined by the thickness of the upper nitride layer for regulating the curvature of the cantilever, with the thicknesses of the other layers constituting the cantilever and the length thereof being constant. In the semiconductor vibration detecting structure according to the present invention, even if vibrations having relatively large vibration levels are applied to the detecting structure, the cantilever of the vibration detecting structure vibrates well but never hits the surface of the semiconductor substrate, thus enabling a wide rage of mechanical vibrations to be detected with a high sensitivity.

Abstract: The invention relates to an apparatus for measuring a force wherein the force to be measured is applied to a beam in an axial direction. Oscillating forces applied transversely to the beam sets the beam in its resonant state and the resulting resonant frequency is an indication of the magnitude of the force.

Abstract: Web tension measurement in that the web (5) is caused to oscillate transversely with the resonance frequency for the portion of the web (5) defined by a support (2,2a). The oscillations are measured by detectors (6,7) for determining the web tension. The measuring is carried out free of contact in that a thin air layer is maintained between the support (2,2a) and web (5).

Abstract: An electret sheet is clamped on an apertured support around the aperture so that a sheet portion stretches all across the aperture. A tension-producing ring is advanced against the sheet portion normal to its stretch direction to produce progressively increasing tension therein. Concurrently, a loudspeaker on one side of the sheet emits constant-amplitude sound waves of fixed frequency and directed against the sheet portion to cause it to vibrate at that frequency. When, because of the increasing tension in the sheet portion, it's vibration amplitude rises to a predetermined value at or near resonance, the advance of the mentioned ring is ended, and the sheet portion is adhered to another ring which retains in that portion the tension then existing in it. Such tensioned sheet and adhering ring are then used to make electret diaphragms for electret microphones.

Abstract: An accelerometer includes a hinged proof mass constrained from movement by a beam resonator force transducer. To afford greater movement of the proof mass and greater latitude in positioning mechanical stops, one end of the force transducer is connected with the accelerometer base through a compliant mount. The other end of the force transducer is connected with the proof mass at the center of percussion of the proof mass. Adjacent surfaces of the proof mass and base provide squeeze film viscous gas damping. A pair of proof mass-force transducer systems are mounted on a carrier in opposite positions with the sensitive axes of the proof masses aligned and the proof mass hinge axes parallel and opposed to each other.

Abstract: A microelectronic device to detect mechanical vibrations and analyze vibration frequencies. The device comprises a vibrator in the form of thin plate supported on a semiconductor substrate in the manner of either cantilever beam or fixed beam. The vibrator is either conductive or coated with a conductive film to serve as a vibratable electrode layer. The substrate is formed with a fixed electrode layer in an area opposite to the vibrator, and an electric circuit to detect a change in the capacitance between the fixed and vibratable electrode layers is integrated with the substrate. For discrimination of vibration frequencies without using any bandpass filter, the device may have a plurality of vibrators different in resonance frequency each paired with a fixed electrode layer.

Abstract: An electro-mechanical load sensor is in the form of a mechanical resonant system with electrostatically coupled electrodes. The mechanical system is formed from a silicon wafer by a selective etching process and comprises a filament of between two terminations 12 and 13 carrying transverse plates M.sub.1 and M.sub.2. Electrostatic (capacitive) coupling to plate electrodes E.sub.1, E.sub.2, E.sub.3 in a self-exciting circuit drives the system. The resonant frequency for angular S vibrations with plates M.sub.1 and M.sub.2 in anti-phase varies with applied load L and is thus a measure of this load.

Abstract: A non-contacting torque sensor is provided for measuring the torque of stationary and slowly rotating shafts. The torque sensor employs an oscillating thin-wall cylinder to produce a signal whose frequency is directly proportional to the torque applied to a shaft. Electromagnetic coils drive the cylinder at its natural frequency and sense its motion to produce a signal that is proportional to torque. Temperature and shaft bending effects are minimized by accordion folds integrally formed at the end portions of the oscillating cylinder.

Abstract: A method of nondestructively detecting the presence of free liquid within a sealed enclosure containing solidified waste by measuring the levels of waste at two diametrically opposite locations while slowly tilting the enclosure toward one of said locations. When the measured level remains constant at the other location, the measured level at said one location is noted and any measured difference of levels indicates the presence of liquid on the surface of the solidified waste. The absence of liquid in the enclosure is verified when the measured levels at both locations are equal.

Abstract: A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

Abstract: A resonator force transducer assembly includes an elongate base element, a first arm disposed generally in parallel with a front portion of the base element, a first hinge joining the arm near a rear end thereof to the base element at about the middle thereof, an elongate resonator element such as a quartz crystal attached to the front ends of the arm and base element to extend therebetween, a second arm disposed generally in parallel with a rear portion of the base element, and a second hinge joining the second arm to the base element. A third hinge joins the front end of the second arm to the rear end of the first arm to form a type of compound lever arrangement so that when a force is applied to the second arm to urge it either toward or away from the base element, a portion of this force is transmitted via the third hinge to the first arm to urge it either away from or toward the base element to thereby stress the quartz resonator element.

Abstract: A differential pressure gauge comprises a balance beam (3) acting upon a vibrating blade (6). The beam (3) and the blade (6) are disposed in a rigid chamber 4 under vacuum. The beam (3) is acted upon by a force, resulting from the deformation of a flexible or expansible chamber (7) subjected to a pressure P.sub.T and disposed in a second rigid chamber (5) subjected to a pressure P.sub.S. A flexible or expansible seal element (9) isolates the chambers but transmits the forces without disturbing them. This gauge has a high precision and delivers information in digital form, particularly useful in aeronautics.

Abstract: Improved measuring apparatus of the vibratory string type including a molded synthetic plastic body member containing a horizontal through passage for receiving the permanent magnet excitation and sensing system, and a pair of integral parallel horizontal wing-like projections that extend from the body member in supporting relation on opposite sides of the exciting magnet system. The body member also contains a through bore arranged in spaced relation directly beneath the through passage, a rear recess being provided in the rear face of the body member for receiving clamping means having a bearing portion that extends through the through bore for connection with the lower end of the vertically arranged measuring string. Additional apertures are formed in the body member for connecting the same to a fixed support or console.

Abstract: A resonant wire instrument for producing a measurement signal, which is derived from the resonant frequency of a vibratable wire tensioned in accordance with the magnitude of a physical variable being measured, wherein a force impulse produced mechanically by an apparatus is applied to displace laterally one end of the vibratable wire so as to excite the wire into resonant motion. In one embodiment, the one end is rigidly attached to a housing and a piston applies a transverse force impulse to that end by momentarily striking the housing. In another embodiment, the one end is connected to a piezoelectric crystal which responds to a short-duration electric field to displace momentarily that end.

Abstract: An accelerometer has two proof masses each constrained from movement by a beam resonant force transducer. The proof mass-force transducer systems are mounted with the sensitive axes of the proof masses aligned and the force transducers arranged so that their resonant frequencies f.sub.1 and f.sub.2 vary oppositely with a change in acceleration. The acceleration is determined in accordance with the relationa=A.sub.1 f.sub.1 -A.sub.2 f.sub.3 +A.sub.0ora=A.sub.1 f.sub.1.sup.2 -A.sub.2 f.sub.2.sup.2 +A.sub.0where a is the acceleration and A.sub.1, A.sub.2 and A.sub.0 are calibration coefficients.

Abstract: A temperature sensor is formed by mounting a force-sensitive resonator on a resilient or non-resilient base structure, preferably in an enclosure such that thermally induced expansions or contractions of the base structure apply a stress to the resonator. The resonant frequency of the resonator is measured to provide an indication of the temperature of the base structure and resonator.

Abstract: A mass and force meter particularly suited for weighing large and bulky loads, for example vehicles, which, in spite of the large dimensions of the load support due to the nature of the load, has a small total height and in which possible unpredictable deformations of the frame do not influence the precision of the measurement, said mass and force meter having a frame, a load support directly supported by two brackets each of which is connected to the frame by means of two flat springs forming a parallel guiding device, a measuring system, springs compensating the main share of the load and an elastic transmission element transmitting to the measuring system the load-proportional remaining share of the load.