Abstract: A cylindrical quartz crystal transducer that exhibits a low probability of twinning, and uses a combination of resonator signal inputs at the B-mode and C-mode frequencies to calculate resonator temperature. Crystallographic orientations are disclosed where combinations of B-mode and C-mode resonant frequencies exist that are sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Such a transducer is usable at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure allows a choice of crystallographic orientation, other characteristics of the transducer, such as increased pressure sensitivity and activity dip-free operation, may be optimized by varying crystallographic orientation.

Abstract: Arrays of resonator sensors include an active wafer array comprising a plurality of active wafers, a first end cap array coupled to a first side of the active wafer array, and a second end cap array coupled to a second side of the active wafer array. Thickness shear mode resonator sensors may include an active wafer coupled to a first end cap and a second end cap. Methods of forming a plurality of resonator sensors include forming a plurality of active wafer locations and separating the active wafer locations to form a plurality of discrete resonator sensors. Thickness shear mode resonator sensors may be produced by such methods.

Abstract: A cylindrical quartz crystal transducer that exhibits a low probability of twinning, and uses a combination of resonator signal inputs at the B-mode and C-mode frequencies to calculate resonator temperature. Crystallographic orientations are disclosed where combinations of B-mode and C-mode resonant frequencies exist that are sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Such a transducer is usable at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure allows a choice of crystallographic orientation, other characteristics of the transducer, such as increased pressure sensitivity and activity dip-free operation, may be optimized by varying crystallographic orientation.

Abstract: A cylindrical quartz crystal transducer that exhibits a low probability of twinning, and uses a combination of resonator signal inputs at the B-mode and C-mode frequencies to calculate resonator temperature. Crystallographic orientations are disclosed where combinations of B-mode and C-mode resonant frequencies exist that are sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Such a transducer is usable at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure allows a choice of crystallographic orientation, other characteristics of the transducer, such as increased pressure sensitivity and activity dip-free operation, may be optimized by varying crystallographic orientation.

Abstract: Arrays of resonator sensors include an active wafer array comprising a plurality of active wafers, a first end cap array coupled to a first side of the active wafer array, and a second end cap array coupled to a second side of the active wafer array. Thickness shear mode resonator sensors may include an active wafer coupled to a first end cap and a second end cap. Methods of forming a plurality of resonator sensors include forming a plurality of active wafer locations and separating the active wafer locations to form a plurality of discrete resonator sensors. Thickness shear mode resonator sensors may be produced by such methods.

Abstract: Arrays of resonator sensors include an active wafer array comprising a plurality of active wafers, a first end cap array coupled to a first side of the active wafer array, and a second end cap array coupled to a second side of the active wafer array. Thickness shear mode resonator sensors may include an active wafer coupled to a first end cap and a second end cap. Methods of forming a plurality of resonator sensors include forming a plurality of active wafer locations and separating the active wafer locations to form a plurality of discrete resonator sensors. Thickness shear mode resonator sensors may be produced by such methods.

Abstract: A cylindrical quartz crystal transducer that exhibits a low probability of twinning, and uses a combination of resonator signal inputs at the B-mode and C-mode frequencies to calculate resonator temperature. Crystallographic orientations are disclosed where combinations of B-mode and C-mode resonant frequencies exist that are sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Such a transducer is usable at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure allows a choice of crystallographic orientation, other characteristics of the transducer, such as increased pressure sensitivity and activity dip-free operation, may be optimized by varying crystallographic orientation.

Abstract: Arrays of resonator sensors include an active wafer array comprising a plurality of active wafers, a first end cap array coupled to a first side of the active wafer array, and a second end cap array coupled to a second side of the active wafer array. Thickness shear mode resonator sensors may include an active wafer coupled to a first end cap and a second end cap. Methods of forming a plurality of resonator sensors include forming a plurality of active wafer locations and separating the active wafer locations to form a plurality of discrete resonator sensors. Thickness shear mode resonator sensors may be produced by such methods.

Abstract: A transducer pressure crystal having improved thermal coupling with the environment external to a pressure housing in which the crystal is disposed. A cylindrical major portion of the side wall of the pressure crystal is located immediately adjacent an inner wall of a chamber within the pressure housing, separated therefrom only by dimensional tolerances sufficient to ensure that the crystal is surrounded by pressure-transmitting fluid exposed to pressure from the external environment. The thermal time constant of the transducer for external temperature changes is significantly decreased. The time constant of the transducer for temperature changes in the pressure-transmitting fluid produced by rapid pressure changes is similarly decreased. A thin, electrically insulating element may optionally be disposed between the crystal side wall and the inner wall to preclude electrical grounding of the crystal to the housing.

Abstract: In a process of producing crystal resonators in which the direction and magnitude of the gamma vector is substantially the same for each resonator, a method of altering the resonator during the process to change the resonator mass, shape, or electrode placement so as to reduce the gamma vector magnitude of each crystal. This alteration may be done by adding mass, removing mass, or both adding and removing mass, or by positioning the electrodes to selectively position the electric field in the crystal, all in order to move the location of the active region of vibration and thereby reduce the gamma vector.

Abstract: Structure for mounting a disc-shaped crystal, having a top and bottom surface, of a crystal resonator includes four attachment pads affixed to the crystal on the bottom surface near the perimeter thereof, four base pads affixed to a base surface, and four generally elongate parallel support elements, each extending from a different one of the base pads to a different one of the attachment pads to support the crystal. The support elements are generally longitudinally rigid and laterally elastic so that lateral movement of the crystal may take place without torque being applied to either the pads or the crystal. In other words, when the crystal is moved sideways, the plane of the crystal remains generally parallel with the previous plane occupied by the crystal.

Abstract: In a process of producing crystal resonators in which the direction and magnitude of the gamma vector is substantially the same for each resonator, a method of altering the resonator during the process to change the resonator mass, shape, or electrode placement so as to reduce the gamma vector magnitude of each crystal. This alteration may be done by adding mass, removing mass, or both adding and removing mass, or by positioning the electrodes to selectively position the electric field in the crystal, all in order to move the location of the active region of vibration and thereby reduce the gamma vector.

Abstract: A resonator assembly comprises a rigid support and a rigid crystal which are rigidly connected along linear segments which have one or more matched thermal characteristics. In a particular embodiment, a thermally matched resonator assembly comprises a Z-cut quartz crystal support, a quartz crystal resonator having an active region and including a crystalline structure oriented relative to X-, Y- and Z-crystallographic axes, which X- and Y-crystallographic axes define an X-Y crystallographic plane; and a rigid connector structure for rigidly connecting the resonator to the support along a segment of a line of a plane parallel to or including the X-Y crystallographic plane, which segment extends across a surface of the resonator and is spaced from the center of the active region of the resonator.

Abstract: A sensor apparatus includes a pressure sensor, a reference device and a temperature sensor collocated within a common environment. The reference device and the temperature sensor are constructed to have temperature response times matched to the temperature response time of the pressure sensor to compensate for temperature gradients produced either by external heating or by pressure-volume heating.

Abstract: In a process of producing crystal resonators in which the direction and magnitude of the gamma vector is substantially the same for each resonator, a method of altering the resonator during the process to change the resonator mass, shape, or electrode placement so as to reduce the gamma vector magnitude of each crystal. This alteration may be done by adding mass, removing mass, or both adding and removing mass, or by positioning the electrodes to selectively position the electric field in the crystal, all in order to move the location of the active region of vibration and thereby reduce the gamma vector.

Abstract: Crystal resonator with low acceleration sensitivity includes a piezoelectric quartz crystal, support structure for holding the crystal and a signal source for causing the crystal to resonate with an active region of vibration. The resonator is modified, if need be, to control (generally reduce) the gamma vector which is a measure of the acceleration senstivity. This may be done by adding mass, removing mass, or both adding and removing mass, all in order to move or change the shape of the active region of vibration and thereby reduce the gamma vector.

Abstract: A sensor apparatus includes a pressure sensor, a reference device and a temperature sensor collocated within a common environment. The reference device and the temperature sensor are constructed to have temperature response times matched to the temperature response time of the pressure sensor to compensate for temperature gradients produced either by external heating or by pressure-volume heating.

Abstract: A quartz resonator pressure transducer includes a generally disc-shaped resonator section adapted to vibrate in response to an oscillatory signal, a housing having sidewalls which generally circumscribe the resonator section and extend in opposite directions generally normal to the plane of the resonator section, and a web, thinner than the resonator section, joining the housing to the perimeter of the resonator section to define grooves between the sidewalls of the housing and the resonator section on the top and bottom sides of the section.

Abstract: A double resonator beam force transducer configured to minimize longitudinal pumping by making the beams vibrate symmetrically. This can be accomplished by making the boundary conditions of the beams symmetrical or, if the boundary conditions are nonsymmetric, then by biasing the beams inwardly or outwardly to compensate for the nonsymmetrical boundary conditions of the beams. In the nonsymmetrical case where the beams would bow outwardly at their fundamental resonant frequency or an odd overtone thereof, an inward bias is provided to minimize longitudinal pumping. In the nonsymmetrical case where the beams would bow inwardly at an even overtone of the fundamental resonant frequency, an outward bias is provided to minimize longitudinal pumping.

Abstract: A vibratory temperature transducer includes a pair of elongate, generally parallel bars coupled together at one end in a type of tuning fork arrangement. The bars each have a thickness of t, a width of w and a length between free and fixed ends of L. The distance between the free end and the point where the bars are coupled together is m. Apparatus is provided to cause the bars to vibrate in torsional opposition, where the frequency of vibration is generally a function of temperature. Apparatus is also provided for determining the frequency of vibration of the bars so that when the bars are subjected to a change in temperature, the temperature can be readily determined by simply determining the magnitude of the frequency change. By careful determination of the dimensions L, m, t and w, spurious modes of oscillation of the transducer, which cause a reduction in the mechanical Q and thus an erroneous reading of temperature, are avoided.