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: A system and apparatus for monitoring physical phenomena and changes in structures which includes a plurality of programmable intelligent transducers arranged in an array, each of which is uniquely addressable by a remote controller to perform its intended measurement functions, translate the analog measurement obtained into digital signals and transmit same to the controller. The monitoring is selective to each individual intelligent transducer. The intelligent transducers combine measurement functions, microprocessor functions and communication functions all programmed and activated from this central controller.

Abstract: A temperature-compensated borehole extensometer comprises a coaxial remotely anchored assembly of a rod and tube formed of materials having disparate linear coefficients of expansion, said assembly being associated with comparator transducers sensitive to relative linear movement of the rod and tube components under the influence of temperatures.

Abstract: A vibratory-wire strain gage has mounting flanges integral to the instrument for disposition of the wire and its low-profile casing in intimate, substantially coplanar relation to the measuring surface.