Pressure transmitter for clean environments

Abstract

A pressure transmitter (14) for clean processing environments is disclosed. The pressure transmitter (14) includes a process connector (48), a weld ring (42), a pressure sensor module (46), a frame (26), and a housing (22). The process connector (48) is coupleable to a source of process fluid (18) and directs process fluid to the pressure sensor module (46). The process connector (48) is sealed to the pressure sensor module (46) to couple process fluid to the pressure sensor (60, 80). A weld ring (42) is disposed about the pressure sensor module (46) and provides a secondary process fluid seal. The pressure sensor module is electrically coupled to measurement circuitry (58) to provide digital data indicative of process fluid pressure. The frame (26) is coupled to the weld ring (42) and the housing (22) is coupleable to the frame (26) and weld ring (42) such that the housing (26) rests upon the weld ring (42) when secured in place. The pressure sensor module (46) includes an isolator diaphragm (76) that is operably coupled to a pressure sensor (60, 80). The pressure sensor (60, 80) includes deflectable sensor diaphragm having elements thereon that provide an electrical characteristic that varies with diaphragm deflection (60, 80) are separated from one another by a filler material (82). The filler material (82) can be polyurethane.

Description

technical field [0001] The present invention relates generally to pressure transmitters, and more particularly, the present invention relates to pressure transmitters for use in clean environments. Background technique [0002] Certain industrial production processes require a cleaner environment than general processing. Examples of such cleaning processes include semiconductor manufacturing, pharmaceutical manufacturing and food processing. In these environments, it is important to ensure that all process equipment can perform its required function without contaminating the process. [0003] One device that has become useful in industrial process environments is a pressure transmitter, which is a device that senses the pressure of a fluid inside a process and provides an electrical signal indicative of the pressure to a control system. Typically, a pressure transmitter has a pressure sensor. The sensor includes a flexible diaphragm that flexes in direct response to pressu...

AI Technical Summary

Problems solved by technology

Pressure transmitters using capacitive pressure sensors are usually filled with a dielectric fluid that increases the capacitance of the pressure sensor to improve sensor resolution, but in the event of a leak in such a sensor, the dielectric filling fluid (sometimes Silicone oil) will overflow into the system, thus contaminating the product

Therefore, those industrial production processes that require a very clean environment do not allow pressure sensors to use filling fluids.

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