AT Cut Coated Quartz Endcaps For Thickness Shear Mode Pressure Sensor

The dual-mode Thickness-Shear Pressure sensors is used in the oil and gas industry. It measures both pressure and temperature and provides increased resolution over previous designs. Range and sensitivity for quartz pressure sensor designs are determined by the resonator and endcap dimensions and crystallographic orientation. Performance objectives for the design include the ability to withstand repeated cycling to pressures exceeding full scale (5000 psig or 34.474 x lo6 Pa) at maximum temperature. Additional performance objectives for the sensor include accuracy better than &0.025% of full scale pressure, repeatability better than &0.015% of full scale, and resolution better than 0.01 psi (68.95 Pa).

A unique feature of the design is a large sealing area to minimize stresses transmitted through the joint to the resonator. Adjacent to the sealing face, the cylinder wall tapers away from the center of the cylinder bore, reducing the cylinder wall thickness and increasing the inner bore radius. The re-entrant endcap design employs a thicker cylinder wall at the resonator interface to minimize joint stresses and a thinner cylinder wall away from the joint to reduce the endcap stiffness and enhance sensitivity.

BonTek can provide the quartz endcaps AND the quartz resonator, both of which are AT-Cut thickness-shear mode.