Silicon capacitance intelligent pressure/differential pressure transmitter and a measurement method thereof

Abstract

The invention belongs to the field of pressure / differential pressure transmitter and especially relates to a silicon capacitance intelligent pressure / differential pressure transmitter and a measurement method thereof, the pressure / differential pressure transmitter comprises a silicon capacitance pressure sensor, a time-to-digit conversion circuit, a single chip machine, a memory, an intelligent display unit, a D / A conversion portion and a Hart protocol processing circuit, wherein an input end of the time-to-digit conversion circuit is connected with an output end of the silicon capacitance pressure sensor; a signal input end of the single chip machine is connected with a signal output end of the time-to-digit conversion circuit; a signal output end of the single chip machine is respectively connected with the input ends of the memory, the intelligent display unit, the D / A conversion portion and the Hart protocol processing circuit; the signal chip machine is internally equipped with a temperature sensor in order to realize the real-time measurement of the temperature of the silicon capacitance pressure sensor; and the single chip machine executes data exchange with the memory, the intelligent display unit and the time-to-digit conversion circuit via SPI bus. The silicon capacitance intelligent pressure / differential pressure transmitter has the advantages of simple structure, low cost, accurate measurement signal and high stability.

Description

technical field [0001] The invention belongs to the field of pressure / differential pressure transmitters, in particular to a silicon capacitor intelligent pressure / differential pressure transmitter and a measuring method thereof. Background technique [0002] In the field of industrial process control, 1151 series pressure / differential pressure transmitter is the most widely used transmitter variety for pressure measurement. In recent years, it is developing in the direction of miniaturization, high precision and intelligence. Most of the products at home and abroad use metal capacitors as sensor materials. [0003] At present, in the front-end signal acquisition of the pressure transmitter, most of the pressure signal acquisition is completed by converting the capacitance signal into a voltage signal through the excitation of the multi-winding oscillating transformer. The stability of the measurement signal in this way is poor. At the same time, because the measurement re...

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Problems solved by technology

The stability of the measurement signal in this way is poor. At the same time, because the measurement result is an analog voltage signal, A / D conversion is required to convert it into a digital quantity and enter the microcontroller system.

This not only increases the cost, but also brings a certain loss of accuracy

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