Abstract: A rotational accelerometer using piezoelectric material, preferably quartz, in a shear orientation. Piezoplates and conducting seismic masses, each having bores therethrough, are bolted to posts that are symmetrically mounted to a body in such a manner that the bolt passes through the piezoplates but does not make contact. The accelerometer can be assembled as a single-axis accelerometer by mounting a pair of posts symmetrically about the body along the measured axis; additionally, the accelerometer may be assembled as a double or triple axis accelerometer by symmetrically mounting additional pairs of posts to the body. The total weight of the seismic masses and the crystals of the shear-type accelerometer halves should be equal. The invention sets forth a novel rotational accelerometer that reduces or eliminates the need for signal-processing electronics.

Abstract: A sensor including a center post extending along the sensing axis of the sensor, a piezoelectric sensing element concentrically engaging the center post, and a preload element preloading the piezoelectric element radially outward to the axis. The center post includes a recess along the axis and the first preload element is in the recess and preloads the piezoelectric element radially outward. The sensor may include a mass concentrically engaging the piezoelectric element. The sensor senses acceleration, force or pressure.

Abstract: A transducer having a regulated power supply for the auxiliary circuits or additional stages using the available power in a transducer module. The voltage required for the regulator is less than lowest transducer circuit output signal as controlled by the output or driver stage. One auxiliary circuit is a self-testing circuit which is responsive to the power-up of the transducer for applying test signals to the transducer for a predetermined time. The tester would include an oscillator for generating test signals in response to a power-up and a disable circuit for disabling the oscillator after the predetermined time as determined by a count of the test signals.

Abstract: An accelerometer (50, 80, 90) provided with a plurality of mounting means for selectively mounting the accelerometer on a test structure. The mounting means include a magnet (64 or 96) carried by the accelerometer (58, 60), a threaded aperture (62) in the housing capable of receiving a mounting stud, and a planar external surface (66, 68; 82; or 94) on the housing, which surface is capable of being secured to the test structure by an adhesive or wax.