Abstract: A silicon accelerometer includes a plurality of silicon layers. The silicon layers form first and second silicon beams supported by flexure members. An acceleration responsive silicon mass is arranged to bend the flexure members in response to accelerations. The silicon beams are vibrated in vacuum chambers and gas damping is provided for the acceleration responsive mass and the flexure members. A sensor is provided for sensing vibration of the first and second silicon beams.

Abstract: A piezoelectric fiber optic phase modulator having a mount at a nodal point of the vibratory system of the modulator. The modulator is excited with an electric field applied in a direction parallel to the axis of the modulator or perpendicular to the radial direction of movement of the modulator. In contrast to the mere hollow cylinder modulator of the related art, the modulator of this invention has a web or center structure integral with the inside surface of the cylinder. The modulator here has a rugged mount, low absorption vibration and negligible harmonics at the mount for efficient and high Q functioning, and has rugged electrical connections for dependable operation.

Abstract: A silicon accelerometer includes several silicon layers. The silicon layers form two silicon beams supported by flexure members. An acceleration responsive silicon mass is arranged to bend the flexure members in response to accelerations. The silicon beams are vibrated in vacuum chambers and gas damping is provided for the acceleration responsive mass and the flexure members. Sensing electronics detect vibration of the two silicon beams.

Abstract: An error control arrangement for an optical fiber rotation sensor having electromagnetic waves propagating in opposite directions passing through a bias optical phase modulator operated by a phase modulation generator both of which can contribute second harmonic distortion resulting in errors in the sensor output signal which are controlled. Control of the bias optical phase modulator contribution for a modulator having a piezoelectric body wrapped with an optical fiber portion is accomplished by mounting the body utilizing layers having nonlinear stiffness.

Abstract: Pressure sensor having a silicon diaphragm chip. The diaphragm in the chip is less than 200 mils in diameter and has an ultrasonic resonant frequency that varies with pressure exerted on it. The chip has resistors with values that change with fluctuation of the chip. The changing resistor values are fed to a supporting electronics that detect the resonant frequency of the diaphragm and indicate measurement of the pressure exerted on the diaphragm. The supporting electronics feed back a signal corresponding to the detected resonant frequency for a sensed pressure to a piezoelectric device that drives the diaphragm to sustain its vibration.

Abstract: A process of bonding crystalline quartz plates in a plate assembly of a quartz crystal resonator is provided. The plate assembly includes a base plate, a resonator plate, a cover plate, a first silver and indium alloy layer between the base plate and the resonator plate, and a second silver and indium alloy layer between the resonator plate and the cover plate. The process of bonding the plates in the plate assembly includes the steps of depositing in sequence on base plate face and on the cover plate face, a layer of chromium, a layer of silver, and a layer if indium, and also includes the steps of depositing in sequence on two opposite faces of the resonator plate, a layer of chromium, and a layer of silver, and also includes the steps in sequence of sandwiching the resonator plate between the base plate and the cover plate to form a plate assembly, then evacuating the plate assembly, compressing the plate assembly, and heating the plate assembly to about 310 degrees centigrade for several hours.

Abstract: A quartz crystal vibrating diaphragm pressure sensor includes a primary quartz crystal body having a diaphragm formed therein and electrodes on each side of the diaphragm for piezoelectrically exciting thickness shear mode oscillations of said diaphragm, said oscillations varying in frequency in accordance with variations in fluid pressures applied to the surfaces of said diaphragm. A second identical or substantially identical diaphragm similarly excited but exposed to a constant pressure provides a reference frequency for providing precision difference frequency pressure measurement and for inherently compensating for ambient conditions affecting both diaphragms.

Abstract: A fluid pressure responsive transducer is disclosed of the kind having a thin flat vibrating diaphragm serving as a wall of a continuous pressure chamber for converting a variable fluid pressure magnitude directly into a variable frequency electrical signal. The thin flat diaphragm, secured only at its periphery to the chamber, becomes progressively stiffer as it is progressively deformed by fluid pressure loading more and more from its flat or unstressed position. A dual cavity configuration of the pressure chamber is formed by a rigid divider wall with a restricted passage therethrough. The effects of disturbing acoustic waves which might otherwise be generated interior of the fluid chamber or within pneumatic lines coupled thereto are thus suppressed.