Abstract: A pressure sensor includes a housing with a cavity. The cavity includes a fill fluid and a compensation material. The fill fluid conveys a pressure from a process fluid through a diaphragm to a sensor. The compensation material reduces a difference of thermal expansions between the cavity and the fill fluid.

Abstract: A remote seal differential pressure transmitter, when installed with its remote seal separated by a vertical distance, has an accurate output signal which is compensated for all temperature effects, including compensation of the sensors' temperature characteristics and compensation of the remote seals' temperature characteristics. Compensation for the remote seals' temperature characteristics must include compensation for the expansion and contraction of the translation fluid used in the remote seals and compensation for changes in density of the translation fluid. The changes in density and the installed height of remote seals specifically create a height/temperature error which must be compensated for when the temperature changes.

Abstract: A pressure transmitter assembly includes a laminated ceramic structure for providing fluid passages as well as a support for a pressure sensor, electronic circuitry, fluid barrier diaphragms and input process fluid connections. The laminated structure is comprised of a plurality of co-fired ceramic layers having the fluid passages molded therein to enable fill fluids within the assembly to apply input pressures as a differential pressure across the pressure sensor. In one embodiment of the invention, three ceramic layers are used while a second embodiment uses four layers with an overload diaphragm captured between two of the layers. The laminated ceramic structure can be extended in either embodiment to include an outer ceramic circuit board which is bonded with a fluid-tight interface with an adjacent one of the other ceramic layers.

Abstract: An adjustable overload mechanism for a differential fluid pressure transmitter includes a first and a second overload control diaphragm and an adjustable spring pressure means for applying an adjustable preload pressure to the control diaphragms. The spring pressure means for each diaphragm includes a spring such as a Belleville washer spring located between a diaphragm back-up plate in contact with a side of the control diaphragm and a wedge shaped support for the Belleville washer spring. A wedge shaped drive means is arranged to be selectively movable with respect to the wedge shaped spring support while maintaining the sloping wedge surfaces in contact. An adjustable drive screw is connected to the drive wedge to provide a means for changing the relative position of the support wedge and drive wedge.