A pressure difference sensor for providing a pressure measurement signal, comprising: a pressure difference measuring cell, which is suppliable with first and second pressures and which outputs the pressure measurement signal; first and second ceramic stiffening elements, each of which is joined with the pressure difference measuring cell and has a duct, via which the first, respectively the second, pressure is suppliable to the pressure difference measuring cell; a platform with first and second pressure input openings, each of which extends from a first surface to a second surface of the platform, wherein the pressure input openings are sealed on the first surface, each with its own isolating diaphragm, and first and second pressures tubes, which are arranged between the stiffening elements and the platform, and wherein each of the first pressure tube and the second pressure tube has at least one bend in a region between the platform and a first, respectively second, connecting area of the corresponding pressure tube.

A pressure sensor, including a platform of ceramic, a measuring membrane arranged on the platform, a pressure measuring chamber enclosed in the platform under the measuring membrane, and at least one metal body connected with the platform via a pressure-tight, preferably elastomer free, mechanical connection. Thermomechanical stresses arising from the connection are reduced by features including that the pressure-tight, mechanical connection occurs via an adapting body arranged between the platform and the metal body. The adapting body has a thermal expansion coefficient, which rises in direction (z) extending from the platform to the metal body from a coefficient of expansion corresponding to a thermal coefficient of expansion of the ceramic of the platform to a coefficient of expansion corresponding to the thermal coefficient of expansion of the metal body, and the adapting body is connected by a first joint with the platform and by a second joint with the metal body.

A capacitance-based pressure sensor for measuring a process variable includes a metal sensor body, a diaphragm disposed within a cavity of the metal sensor to form a deflectable capacitor plate, and an insulator extending through the metal sensor body from an end wall to the cavity. The pressure sensor further includes an isolation tube in fluid connection with the cavity, the isolation tube extending into the insulator through the end wall, a stationary capacitor plate on a surface of the insulator in the cavity, the stationary capacitor plate spaced from the diaphragm, and an electrical lead wire connected to the stationary capacitor plate and extending through the insulator parallel to the isolation tube and exiting the insulator at the end wall. A fill fluid is within the isolation tube and the cavity to apply pressure to the diaphragm.

A remote seal assembly for a process transmitter includes a seal body containing a cavity sealed by a diaphragm. The seal body configured to be mounted to a process element containing a process fluid such that a first side of the diaphragm is exposed to the process fluid. A capillary contains a fill fluid that is in fluid communication with the cavity and a second side of the diaphragm. A coupling has a capillary recess and two cavities separated by a second diaphragm. The capillary extends through the capillary recess and connects to the coupling such that the fill fluid in the capillary is in fluid communication with one of the two cavities and the second diaphragm. A thermally conductive element preferably extends continuously along the capillary from the seal body toward the coupling and into the capillary recess without contacting the coupling.

A pressure transmitter assembly for measuring a process pressure of an industrial process includes a pressure sensor configured to sense the process pressure. A process coupling couples the pressure sensor to the industrial process. In one example configuration, a phase change material carried in the process coupling is configured to reduce heat transfer from the industrial process to the process variable sensor by changing phase in response to heat from the industrial process. In another example configuration, a thermocouple electric cooling element is coupled to the process coupling and configured to conduct heat away from the coupling in response to an applied electric current.

A pressure transmitter assembly for measuring a process pressure of an industrial process includes a pressure sensor configured to sense the process pressure. A process coupling couples the pressure sensor to the industrial process using an elongate housing with a fill fluid capillary. In one example configuration, at least one thermoelectric element is included within the elongate housing to apply heat to, or conduct heat away from, the process coupling in response to an applied electric current or signal, allowing fill fluid to be preheated to facilitate cold startup or calibration, and providing cooling of the process coupling during high temperature operation.

This disclosure provides example methods, devices and systems associated with flat covered leadless pressure sensor assemblies suitable for operation in extreme environments. In one embodiment, a system may comprise a semiconductor substrate having a first side and a second side; a diaphragm disposed on the first side of the semiconductor substrate; a first cover coupled to the first side of the semiconductor substrate such that it overlays at least the diaphragm, wherein a pressure applied at the first cover is transferred to the diaphragm; and a sensing element disposed on the second side of the semiconductor substrate, wherein the sensing element is used to measure the pressure.

A cylinder internal pressure sensor configured to be subjected to heat of combustion inside a combustion chamber and a pressure inside the combustion chamber, and including: a housing; a diaphragm joined to one end of the housing and being configured to deflect according to the pressure inside the combustion chamber; a sensor element housed inside the housing, being coupled to the diaphragm; and being configured to change a signal to be output according to a temperature inside the combustion chamber and the pressure inside the combustion chamber; a heating element configured to heat the sensor element; and a control unit configured to control the amount of heat generated by the heating element such that the temperature of the sensor element becomes higher than a first predetermined temperature that is the temperature of the sensor element when subjected to the heat of combustion is provided.

A pressure sensor system having a pressure sensor chip is specified. The pressure sensor chip is mounted on a mounting receptacle of a ceramic housing body having a pressure feed guided to the pressure sensor chip. The housing body is three-dimensionally shaped and monolithically formed and is formed by a ceramic material having a coefficient of thermal expansion which deviates by less than 30% from the coefficient of thermal expansion of the pressure sensor chip in a temperature range of greater than or equal to 40 C. and less than or equal to 150 C.

A glow plug adaptor for pressure measurement in a combustion chamber of an internal combustion engine includes an adaptor sleeve attached to an adaptor head that contains a pressure sensor with a diaphragm. A sealing shoulder can be screwed into an opening in a combustion chamber to provide a pressure-tight seal and permit passage of signal conductors from the pressure sensor through the adaptor sleeve. The adaptor head is tapered at the proximal combustion chamber end, and in the adaptor head a cavity is formed in such a way that the cavity is bounded by the diaphragm of the pressure sensor mounted therein and by a closed end wall of the adaptor head.