摘要:
A pressure monitoring system provides a pressure sensor and a body that has a first coefficient of thermal expansion and includes at least one opening for accessing a process fluid. At least one isolation diaphragm is coupled to the body and positioned in the at least one opening. The at least one isolation diaphragm has a first surface in communication with the process fluid. At least one passageway is located in the body and configured to contain a fill fluid in communication with a second surface of the first isolation diaphragm. The at least one passageway is positioned between the first isolation diaphragm and the pressure sensor. At least one expansion chamber is coupled to the first passageway and includes an insert having a second coefficient of thermal expansion. The first coefficient of thermal expansion of the body is greater than the second coefficient of thermal expansion of the insert.
摘要:
A pressure monitoring system provides a pressure sensor and a body that has a first coefficient of thermal expansion and includes at least one opening for accessing a process fluid. At least one isolation diaphragm is coupled to the body and positioned in the at least one opening. The at least one isolation diaphragm has a first surface in communication with the process fluid. At least one passageway is located in the body and configured to contain a fill fluid in communication with a second surface of the first isolation diaphragm. The at least one passageway is positioned between the first isolation diaphragm and the pressure sensor. At least one expansion chamber is coupled to the first passageway and includes an insert having a second coefficient of thermal expansion. The first coefficient of thermal expansion of the body is greater than the second coefficient of thermal expansion of the insert.
摘要:
A two-wire transmitter senses a pressure using an internal pressure sensor. The transmitter includes an input for receiving a process variable from a remote sensor which is separated from the transmitter. Circuitry in the transmitters transmits information on a two-wire process control loop which is related to the sensed pressure and the process variable.
摘要:
A process fluid pressure measurement system includes a process fluid pressure transmitter coupled to a coplanar manifold. The coplanar manifold includes a first bore coupleable to a source of process fluid, and a vent passageway connected to the first bore and terminating in a vent hole. The coplanar manifold includes at least one port configured to receive a valve stem. Directly engaging the valve stem with the coplanar manifold selectively vents the coplanar manifold. Aspects of the present invention also include a coplanar manifold for coupling fluid to a process fluid pressure transmitter, and a method of venting such a coplanar manifold.
摘要:
A metal thin film bonds a semiconductor bonding region of a diaphragm layer to a ceramic bonding region of a high modulus support block. The arrangement isolates a pressure sensing diaphragm from undesired strain, improving sensor accuracy. A passageway through the support block couples the fluid pressure to the sensing diaphragm to deflect it. Capacitive coupling between the diaphragm and a capacitor plate on the support block sense the deflection and provide an output representative of pressure.
摘要:
A process fluid pressure measurement system includes a process fluid pressure transmitter coupled to a coplanar manifold. The coplanar manifold includes a first bore coupleable to a source of process fluid, and a vent passageway connected to the first bore and terminating in a vent hole. The coplanar manifold includes at least one port configured to receive a valve stem. Directly engaging the valve stem with the coplanar manifold selectively vents the coplanar manifold. Aspects of the present invention also include a coplanar manifold for coupling fluid to a process fluid pressure transmitter, and a method of venting such a coplanar manifold.
摘要:
A two-wire transmitter senses differential pressure, absolute pressure, and process temperature of a process fluid. The information can be used to provide an output representative of mass flow through a pipe. The transmitter has an electronics module housing attached to a sensor module housing. The sensor module housing contains all the sensors for the pressures and includes a boss input for receiving a signal representative of a temperature or pressure signal. The three process variables are appropriately digitized, and received by an electronics circuit board in the electronics housing including a microprocessor for calculating the mass flow. The microprocessor in the electronics housing also calculates a compressibility factor and a discharge coefficients according to a polynomials of specific forms. The boss is integral to the sensor module housing and is adapted to fit either shielded twisted pair cabling or conduit.
摘要:
A process fluid pressure transmitter has a remote pressure sensor. The transmitter includes an electronics housing and a loop communicator disposed in the electronics housing and being configured to communicate in accordance with a process communication protocol. A controller is disposed within the electronics housing and is coupled to the loop communicator. Sensor measurement circuitry is disposed within the electronics housing and is coupled to the controller. A remote pressure sensor housing is configured to couple directly to a process and is spaced from the electronics housing. A pressure sensor is disposed within the remote pressure sensor housing. The pressure sensor forms at least one electrical component having an electrical characteristic that varies with process fluid pressure. Portions of the electrical component are coupled directly to a multiconductor cable that operably connects the pressure sensor to the sensor measurement circuitry.
摘要:
A process fluid pressure transmitter includes a pressure sensor, transmitter electronics, and an isolation system. The pressure sensor has an electrical characteristic that changes with pressure. The transmitter electronics are coupled to the pressure sensor to sense the electrical characteristic and calculate a pressure output. The isolation system includes a base member, and isolation diaphragm, and a fill-fluid. The isolation diaphragm is mounted to the base member and interposed between the pressure sensor and a process fluid. The fill-fluid is disposed between the isolation diaphragm and the pressure sensor. The base member and the isolation diaphragm are constructed from different materials such that the coefficient of thermal expansion of the isolation diaphragm is larger than the coefficient of thermal expansion of the base member.