Abstract: A pressure transmitter with a fluid isolator that includes a sensor tube and a fill tube that have “D” shaped ends that connect together in a port internal to the transmitter. The shaped ends can be brazed into the port for sealing. Fitting both the sensor tube and the fill tube in the same port provides a low cost isolator with reduced isolator liquid volume. The fluid isolator has an isolator diaphragm with a central diaphragm region overlying a central backing plate that includes a annular groove. The annular groove avoids slow response of the isolator after an overpressure condition.

Abstract: A pressure transmitter with a transmitter housing having an outer wall providing thermal resistance. The outer wall extends from an isothermal island at a first end to a heat sink island at a second end. The isothermal island includes a fluid inlet, and pressure and temperature sensors. The heat sink island includes a primary heat load device that is heat sunk to an outer shell of an electrical connector. The connector contacts carry a current controlled by the transmitter, and a portion of the current is conducted by a primary heat load device. A circuit board controls the current to represent the pressure. A high accuracy, temperature compensated current output represents pressure.

Abstract: A process control instrument adapted to provide an output indicative of a parameter of a process fluid is disclosed. The process control instrument is designed to be attachable to a flange having a first passageway filled with process fluid. A body of the process control instrument has an opening adjacent to the first passageway adapted to receive process fluid from the first passageway. An isolation diaphragm is positioned in the opening of the body and separates the opening and the first passageway from a second passageway. A weld ring positioned in the opening is adapted to evenly distribute an attachment force across a support surface such that damage to the isolation diaphragm is minimized.

Abstract: A process control instrument adapted to provide an output indicative of a parameter of a process fluid is disclosed. The process control instrument is designed to be attachable to a flange having a first passageway filled with process fluid. A body of the process control instrument has an opening adjacent to the first passageway adapted to receive process fluid from the first passageway. An isolation diaphragm is positioned in the opening of the body and separates the opening and the first passageway from a second passageway. A weld ring positioned in the opening is adapted to evenly distribute an attachment force across a support surface such that damage to the isolation diaphragm is minimized.