Pressure transmitter for measuring the pressure of a process fluid and related method

摘要

A pressure transmitter and method for measuring pressure exerted by a fluid on the diaphragm of the pressure transmitter. A pressure sensor assembly can include a diaphragm displaceable under pressure exerted by the fluid, and first and second electronic circuits generating first and second oscillating signals, respectively, whose frequencies depend on the displacement of the diaphragm. First and second numerical values which are representative of the oscillating frequencies of the first and second oscillating signals, respectively. A signal indicates pressure exerted by the fluid on the diaphragm based on the first and second calculated numerical values.

主权项

1. A pressure transmitter, comprising:
a pressure sensor assembly having a diaphragm displaceable under pressure exerted by a fluid, a first LC oscillating circuit and a second LC oscillating circuit positioned on opposite sides with respect to said diaphragm, in which each inductance varies as a function of the displacement of said diaphragm while each capacity is constant, wherein said first LC oscillating circuit is excited by a first predefined series of pulses to generate an output of a series of consecutive first oscillating signals, wherein said second LC oscillating circuit is excited by a second predefined series of pulses to generate an output of a series of consecutive second oscillating signals, the oscillating frequency of said consecutive first oscillating signals and of said consecutive second oscillating signals depending on the displacement of said diaphragm, and wherein said first predefined series of pulses and said second predefined series of pulses are generated by a first electronic network and a second electronic network, respectively; first electronic means for calculating a first numerical value which is representative of the oscillating frequency of said consecutive first oscillating signals, and a second numerical value which is representative of the oscillating frequency of said consecutive second oscillating signals, said first electronic means driving said first and second electronic networks; and second electronic means which generate a signal indicative of pressure exerted by said fluid on the diaphragm based on said first and second numerical values, wherein said second electronic means is configured to calculate a difference between two consecutive signals indicative of the pressure exerted by said fluid on the diaphragm and, whenever said difference exceeds a predefined second threshold, send a command signal as an input to said first electronic means so as to reduce the time interval during which each numerical value representative of the oscillating frequency of said consecutive first oscillating signals and of said consecutive second oscillating signals is calculated.