Abstract: A vibrating beam force-frequency transducer has a flat elongate blade designed to be interposed between two elements for applying a longitudinal force to the blade. The middle portion of the blade constitutes two lateral beams which are separated by a gap and which are interconnected by terminal portions of the blade. The beams carry electrodes for setting the beams into vibration in the plane of the major faces of the blade and for measuring the frequency of vibration. The terminal portions have extensions parallel to the beams and directed towards the middle of the blade in the longitudinal direction. The extensions are arranged for connecting them to the elements in zones that are closer together than are the terminal portions.

Abstract: A vibrating force transducer suitable for use in a pendular accelerometer mprises a flat elongated strip of piezo-electric material having end portions arranged for being securely connected to elements which apply a force to be measured along the direction of elongation when the transducer is in service. The strip is fractionated by slits parallel along the direction of elongation and orthogonal to major faces of the strips into a central beam and lateral beams which are in a common plane, the lateral beams carrying electrode means for flexural vibration in the common plane at a resonance frequency indicative of the value of the force applied to the end portions and the central beam carrying a resistive temperature sensor.

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.