Research on Automatic Calibration Method Based on ADA4557

Abstract

The pressure transmitter is an instrument that converts the original pressure variable into a quantifiable standard electrical signal output, and its electrical signal has a continuous function relationship with the pressure variable. The traditional manual calibration method requires manual operation to calibrate the pressure transmitter during the calibration process, which is easy to introduce errors and has poor reliability. In order to solve some of the shortcomings of traditional calibration, this paper studies the automatic calibration method based on the ADA4557 signal conditioning chip. Using the actual output value and standard output value under three sets of known pressure points, the curve coefficient of the second-order equation is obtained by the least square method. Thus, the correction coefficient is calculated and written into the pressure transmitter to complete the calibration. After calculation and verification, the calibration method has greatly reduced the calibration time, from the traditional average calibration time of 50 seconds to about 14 seconds, which can smoothly realize the automatic calibration of the pressure transmitter, and the calibration effect is obvious.