Development Of The Integrated Electromagnetic Testing Instrument

The combination of different detection methods is of great significance to ensure the safe operation of industrial equipment.The integration of testing equipment is a hotspot in the current research of non-destructive testing(NDT).Under the support of the National Key Foundation for Exploring Scientific Instrument Program,the development of the integrated electromagnetic testing instrument which can realize magnetic flux leakage(MFL),thickness measurement with electromagnetic acoustic transducer(EMAT)and magnetostrictive guided wave(GW)testing is studied.Firstly,based on the testing principle analysis of MFL,EMAT and GW,a technical solution of integrated electromagnetic testing instrument is proposed based on the field programmable gate array(FPGA)and the network protocol chip.The technical solution realizes the integration of testing instruments with MFL,EMAT and GW on chip level and improves the portability of the instrument.Secondly,the hardware circuit is designed and the corresponding software of the integrated electromagnetic testing instrument is developed.On the basis of detailed analysis of the characteristics of multichannel MFL,EMAT and GW testing,different forms of multi-channel switching circuit are designed.The design of key hardware circuit and the overall circuit production of the testing instrument is completed.Then,a hardware processing algorithm of electromagnetic ultrasonic signal based on multiple echo "plus" operation is proposed,which improves the anti-interference ability of the electromagnetic ultrasonic signal.And a method of packing magnetic leakage data and electromagnetic ultrasonic data is given.The software integration of the electromagnetic testing instrument is realized after the development of the data transmission protocol.Finally,the integrated electromagnetic testing instrument is developed and the performance test is completed.Besides,the application of the integrated electromagnetic testing instrument is extended according to different detection conditions.The results show that the performance of this instrument can meet the design specifications.The tank bottom plate detector can achieve the optical fiber transmission of MFL data,electromagnetic ultrasonic automatic crawling detector can achieve the wireless transmission of thickness data,pipeline composite detector can complete the MFL and circumferential GW inspection on the hole defect.The development of the integrated electromagnetic testing instrument will enhance the detection efficiency of electromagnetic non-destructive testing methods and promote the application of electromagnetic non-destructive testing technology.