Research On Automatic Measurement&Calibration System Of Charge Amplifier Based On LabVIEW

Charge amplifier is a kind of pre-amplifier of piezoelectric sensor,which is widely used in industrial sectors,so its performance directly affects the measurement calibration or test results.The Metrology Law also stipulates that the measuring instruments used for metrological calibration and measurement can be put into use only after they have been verified to be qualified by the legal metrological institutions.At present,most of the measurement and calibration methods of charge amplifier adopt the traditional manual method,which not only brings a lot of workload to the measurement personnel,but also easily produces some misoperation,such as reading and recording errors,and some misoperation may damage equipment,and even threaten personal safety.This paper studies the automatic measurement and calibration system of charge amplifier based on LabVIEW,and establishes an automatic measurement and calibration system which can realize the automatic measurement and calibration of various charge amplifier according to JJG 338-2013 Verification Regulation of Charge Amplifiers.It can automatically measure and calibrate various charge amplifiers,analyze and process data,judge the qualifications and generate measurement reports.The research mainly includes: surveys and researches of charge amplifiers measurements,researches of charge amplifier measurement related theories,research and implementation of verification regulation,overall and detailed design of hardware,design and implementation of multi-functional converter,software design,software programming,system debugging,system validation test and system measurement uncertainty evaluation.Firstly,this paper analyzes the metering characteristics of charge amplifiers,puts forward the expected technical specifications of the system,expounds the composition of an automatic metering and calibration system;designs and realizes a multifunctional converter through practical use,which not only meets the requirements of automatic switching calibration items and standard capacitors in automatic metering and calibration,but also reduces the input noise and improves the test accuracy;integrated completed the hardware equipment required by system,set up a charge amplifier automatic measurement and calibration system.Secondly,the software design based on LabVIEW programming language is studied,the modular hierarchical structure is designed,the program flow is analyzed,the interface design,program programming and debugging release are carried out,and the software development and implementation of the system are completed.Finally,the verification test and measurement uncertainty evaluation of the system are carried out.The result show that the function of the system meets the design requirements,and the calibration of secondary class B charge amplifiers can be carried out.Compared with the traditional manual calibration device,the time of verifying a typical charge amplifier is shortened from 4-6 hours to about 35 minutes,which greatly improves the performance of the system.Work efficiency has been improved.In addition,the measurement uncertainty of the system has been greatly reduced,and its test quality is higher,which can better guarantee the calibration of charge amplifier.