| In these days electronic communication technology and computer control technology is highly developed.As the connection between the physical world and the information world,data acquisition technology is more and more widely used in all walks of life.In this paper,a special high-precision data acquisition system is developed for the special temperature and precison for a special purpose.This paper first studies the structure and design method of high precision data acquisition system both at home and abroad.And then it analyzes the temperature and precision requirement of this data acquisition system in this subject.On this basis,a set of special high precision data acquisition system is developed for this subject.The main research contents include system overall design,system hardware design,software design and system function and accuracy verification in special temperature environment.Firstly,the error theory is introduced.Based on this theory,the error distribution theory is used as the guiding ideology to analyze the possible errors in the data acquisition system and the overall scheme of the system is designed in order to decrease possible errors.Modular design is used in the development of data acquisition,we divide the system into several partments which includes signal conversion,signal condition,signal isolation,channel switching,range switching,data storage and transmission,temperature control.Secondly,the hardware design and device selection of each module are completed.In the hardware design,the precision of the subject and the requirements of the special temperature environment are taken into account,and the errors that may increase the precision are also taken into account.We compare several handware design methods,the most suitable hardware design scheme and the most suitable component selection are given.After the hardware design is completed,we developed all software with the help of STM32 and KEIL.Finally,completing the entire data acquisition system structures according to the design of hardware and software.This chapter show the picture of every part of this system.We put the data acquisition system in the incubator and then change the temperature between-55℃ to 80 ℃.At the same time we record the result of all the 22 channel and then compare them with standard values which is measured by Keysight 34401.The result show that our data acquisition system meet the demand which is set in the first chapter. |
