Design And Realization Of Automatic Verifcation System Of Sound Level Meter Based On LabVIEW

As the most common instrument to measure sound pressure level,Sound Level Meter is widely used,so it is of great significance to ensure its measurement accuracy.However,the verification process of Sound Level Meter is complex.With the increasing number of Sound Level Meters sent for daily inspection,it is difficult for the Measurement Institute to cope with the manual verification method.Therefore,combined with the verification regulations and the actual situation of the verification work of the Measurement Institute,an automatic verification system of Sound Level Meter based on LabVIEW is proposed to reduce the workload of verification personnel and improve the verification efficiency and accuracy of verification results.In terms of hardware,the system takes the multi serial industrial computer as the control core,and relies on the virtual instrument technology to provide standard interfaces for all the instruments that need to be programmed,integrating them into a single system.The Key Sight 33520 B signal source is used to replace the original sine signal generator and sudden sound signal generator,which simplifies the standard instrument and improves the accuracy of the output electrical signal.In terms of software,the system adopts LabVIEW Actor Framework,applies object-oriented packaging,inheritance and polymorphism technology,constructs hardware virtual layer packaging standard instruments and equipment and sound level meter to be tested,and tests the verification process and indicators of each verification part of the virtual layer packaging sound level meter.The overall structure of the system software is divided into three levels: the top-level interactive main program,which is user-oriented and can call each verification function module to realize the user's monitoring and management of the whole verification process;the middle level function module includes each part of the sound level meter verification timing and the functions of manual verification,uncertainty evaluation and report generation The bottom instrument driver includes the control driver of standard instrument and sound level meter.Each functional module is built by "class" which is encapsulated.The modules cooperate with each other,and the coupling is low.The system software runs efficiently and stably.The system can realize the automation of instrument control,data acquisition,data analysis and processing,and original data record report generation in the verification of Sound Level Meter.The frequency range of Sound Level Meter can be1 Hz ? 200 k Hz,and the dynamic range of sound pressure level can be 110 d B.After many times of examination and verification,the system works stably and reliably,and the verification time is reduced to half of manual verification,which effectively improves the verification efficiency of sound level meter;all verification data are time anchored to ensure its accuracy.In addition,automatic time identification is realized for all test data by the design of software synchronization and delay function,the uncertainty of manual verification reading is eliminated,and the accuracy of verification results is improved.The system software has good reusability and extensibility,which reduces the difficulty of subsequent expansion of different types of Sound Level Meter.