Abstract: A sensor of force or viscosity or other attributes of a fluid comprises a mechanical resonator (10) including an element (11; 18; 123) of which the stiffness at least partially determines a modal shape of the resonance of the resonator and means (21-23) for measuring a variation of a measure of the resonance as the stiffness of said element changes. The resonator (10) may comprise two beams (10a, 10b; 120, 121) connected at or near one end by a yoke (12; 122) which provides a clamped condition of the resonator at said one end and connected at or near another end by said element.

Abstract: A mechanical resonator system such as a vibrational viscometer includes two distinct resonators, connected by a nexus. The system is capable of vibration in anti-phase with a first vibrational node in the region of the nexus and at least a second node. A compliant support is provided in the region of the first node and a semi-rigid support in the region of the second node.

Abstract: A mechanical resonator system such a vibrational viscometer comprises two distinct resonators, connected by a nexus and being capable of vibration in anti-phase with a first vibrational node in the region of the nexus and at least a second node, a compliant support in the region of the first node and a semi-rigid support in the region of the second node.

Abstract: A transducer includes a resonant structure having a first spring-mass system extending to a connection mass or nexus to which is connected a second spring-mass system, which includes a sensing element. The two spring-mass systems vibrate in antiphase. The nexus is connected to a mechanical datum provided by a mounting by means of a semi-rigid connection member which is preferably stiffer than the first member and which can control the relative motions of the first and second spring-mass systems. The sensing element contains a re-entrant resonator constituted by a spring-mass system, which can be used to adjust the characteristics of the transducer.

Abstract: A transducer measures density, viscosity, flowrate or suchlike of fluids or flowable solids using a resonator having two vibratile beam elements, one of which is disposed coaxially within the other. The outer element may be a closed tube which forms a chamber around the inner element. A drive and sensor may be disposed on a base which provides a common root for the beam elements.

Abstract: An instrument for the detection or measurement of attributes of a material comprises at least one vane which is mounted on a support that allows the vane to vibrate, a drive transducer which is disposed relative to the vane to stimulate vibration therein and at least one sensing transducer disposed to sense the vibrations.

Abstract: A device for measurement of moisture in a body of particulate material, such as a grain in a pile or in a silo, is in the form of a spear with a set of conductive plates 2 carried at one end of a shaft 1 for immersion in the body of particulate material, and a read out meter 4 and carrying handle 3 at the other end of the shaft. Normally the set of conductive plates measure capacitance of the material via a phase locked loop oscillatory circuit. The plates are disposed and shaped to facilitate entry into and removal from the body of particulate material.