The Research On Temperature Drift Compensation Of NTC Resistor Network And Programmable Amplifier Circuit In Starin Measurement

Strain measurement technology plays an important role in important engineering projects.Strain measurement analysis is needed to ensure the reliability of engineering monitoring and the accuracy of material quality parameters in both important engineering structure monitoring and special material quality research.As different measurement methods have dfferent accuracy and application range So,it's of great importance to choose the appropriate measurement method especially for the monitoring of important projects and the evaluation of special materials.Among the many existing measurement methods,we select the strain electrical measurement method which has high precision,wide application range,high sensitivity coefficient and large range,and then build and optimize the system.However the strain electrical measurement method is based on W heatstone Sensitive bridge So it has a serious system temperature drift problem,which is one of the main factors limits the accuracy of strain measurement,so temperature drift problem is an very urgent problem to be solved.The temperature drift of the resistor is one of the important reasons for the excessive error of the strain measurement system,to solve this problem.This article has carried out the following work:(1)Design and build an Negative Temperature Coefficient(NTC)resistor network which is used to solve the problem of excessive temperature drift.Firstly,we study the temperature effect of the resistor,secondly,measure the temperature coefficient of the resistor to be compensated by the experimental method,and used the NTC resistor network compensation method proposed in this paper to compensate the temperature drift of the resistor.Finally,the NTC resistor network compensation method is applied to the temperature drift compensation of the external gain resistor in the bridge arm resistance and the amplifying circuit,thereby solving the temperature drift problem of strain measurement.(2)Using the AD8231 amplifier in the programmable amplifier circuit,to solve the temperature drift problem of the strain measurement from the perspective of structural optimization.Mainly use the AD8231 built-in instrumentation amplifier to amplify the bridge signal,use the built-in operational amplifier to build the filter circuit,and concentrate the amplification filter circuit in the traditional circuit to the AD8231,and avoid using the external gain resistor to set the amplification factor.The structural design of the strain measurement circuit is optimized,thereby solving system's temperature drift.(3)The above two resistance compensation methods are analyzed and summarized.The NTC resistance network compensation method is not only applicable to the strain electrical measurement method,but also can be extended to other resistance systems with resistance temperature drift problems.The structural optimization design of the AD8231 amplifier of the program-controlled amplifier circuit is not only applicable to the strain electrical measurement method,but also can be applied to other strain measurement methods.