Design And Implementation Of Low Resistance High Precision Analog Resistance Reference Source

With the continuous maturation and improvement of electronic information technology,measuring equipment and measuring instruments have become the source of numerous data in various fields such as military,industrial and civil use,and have received increasing attention from all walks of life.In the process of using measuring equipment and instruments,it is necessary to ensure the accuracy and stability of the measurement.Therefore,a more accurate reference source is required to calibrate various types of measurement equipment so as to satisfy the measurement accuracy requirements.The analog resistance reference source is an important part of the calibration equipment,and its continuous improvement in accuracy is of great significance.However,the analog resistance reference source has special characteristics under low-resistance conditions.Even the industry-accepted FLUKE 5520 A has a certain gap between its low-value resistance and its optimal index.The low-resistance high-precision analog resistance reference source studied in this project aims to study the key technologies that improve the accuracy of the system,and provides corresponding solutions for the unique problems of low resistance value,so as to realize a low-resistance analog resistor.The breakthrough of the reference source in terms of accuracy means that the accuracy of the system reaches the required 30 ppm + 0.001?,which exceeds the FLUKE 5520 A corresponding gear index.The results of this project are of great significance for advancing the development of multi-function calibrators in our country,especially the development of low-resistance gears for analog resistance reference sources.The specific research content is as follows:Firstly,this topic carries on the detailed analysis to the function and the performance index of the low-resistance and high-accuracy analog resistance reference source.According to the index requirements,the overall system plan is designed,including the system hardware circuit design and the software overall plan design.Use the simulation software to analyze the feasibility of the circuit scheme.Secondly,this subject researches in depth the key technology of precision improvement of the analog resistance reference source,analyzes and classifies the error of the analog resistance reference source system as a whole,and explains the reason for its occurrence.Then based on different types of error sources,the tolerance analysis and tolerance design techniques,resolution-based digital-analog conversion technology and system software error compensation algorithms are studied.Finally,combining the research results with the requirements of the specific indicators of the project,the purpose of improving the overall accuracy of the system has been achieved through the selection of actual devices,hardware circuit design and software control program design.Again,according to the results of the overall design proposal and the improvement of key technologies,the system hardware circuit design and software design were implemented.The hardware circuit design includes the circuit design of the overall hardware circuit design,signal input circuit,and digital-to-analog converter circuit;the software design includes FPGA internal logic design and automatic test software design,and the control system realizes range switching,data conversion and automatic test functions..Finally,a test verification platform with a low-resistance high-precision analog resistance reference source is built,a system test plan is designed,and a comprehensive and detailed performance index test is performed on the designed low-resistance analog resistance reference source.Test and verification results show that the low-resistance analog resistance reference source designed by this project meets the design index.