Ferrofluid modified fill fluid for pressure transmitters

摘要

A pressure transmitter for measuring a pressure of a process fluid comprises a transmitter housing, a pressure sensor, a hydraulic relay system, a ferrofluid and transmitter electronics. The capacitance-based pressure sensor senses the pressure of the process fluid and is disposed within the housing. The hydraulic relay system comprises an isolation diaphragm positioned on an exterior of the transmitter housing, and an isolation tube extending from the pressure sensor to the isolation diaphragm. The ferrofluid is located in the isolation tube to transmit a change in the pressure of the process fluid at the isolation diaphragm to the sensor. The transmitter electronics are positioned within the housing and are configured to receive and condition a pressure signal from the pressure sensor.

主权项

1. A pressure transmitter for measuring a pressure of a process fluid, the pressure transmitter comprising:
a transmitter housing; a pressure sensor for sensing the pressure of the process fluid, wherein the pressure sensor is disposed within the housing; a hydraulic relay system comprising:
a first isolation diaphragm positioned on an exterior of the transmitter housing; anda first isolation tube extending from the pressure sensor to the first isolation diaphragm; a first ferrofluid located in the first isolation tube for transmitting a change in the pressure of the process fluid at the first isolation diaphragm to the sensor; and transmitter electronics positioned within the housing, the transmitter electronics configured to receive and condition a pressure signal from the pressure sensor.