Design Of Data Acquisition System For Large Pipe Ultrasonic Testing

Presently，Ultrasonic testing is a widespreadly used nondestructive inspection method,which has powerful capacity to check the flaws of materials and components in surface andinward. Integrated with other subjects, the ultrasonic testing technique is developing towardautomatization, digitization and intelligent. With the development of modern computertechnology, computer technology is integrated into the non-destructive testing, making theultrasonic detection technology is gradually moving in the automation, digitization, intelligentdirection, greatly improving the detection efficiency, and increase the reliability of thedetection.Paper combines practical engineering, a special type of pipe for the detection of objectson the basis of analysis of the ultrasound probe type and function, select the appropriate probe,ultrasonic transmitting circuit design, signal conditioning circuit to receive the weak signalprocessing, as well as DSP as the core of the scan control module circuit; to using PXI9820high-speed capture cards, to achieve high-speed signal acquisition. PXI bus computersdeveloped based on the LabWindows/CVI ultrasonic detection software system to achieveautomatic control of the ultrasonic testing process, data acquisition and processing, datastorage and real-time echo signal subsequent ultrasonic testing of image processing and defectidentification laid the foundation.Based on the study on the sonic-wave characteristics of the ultrasonic prober and thestructural system of the usually pulse signal reflecting ultrasonic prober, this paper brings upan idea that integrates traditional nondestructive inspection technique with moderninformation technique, researche and design the automatic control, data acquisition andprocessing system so as to realize precise testing for a type of large pipe. The focusing energyexchanger which have sound beam focusing feature，serves as the testing prober to reduce theattenuation of the ultrasonic information resulted by the checked components. The scancontroller for mechanical scan device carrier has been designed to precisely control the placeof the energy exchanger when testing. For the sake of gaining direct testing and precise results,the ultrasonic scan, carrier control, data acquisition, data storage and processing wereintegrated. Through the data results, flaws qualitatively and quantitatively analysis could berealize. Testing results show that the system could fulfills automatic steping and position fixingof carrier of testing prober, and could locate the flaws in under detecting pipe. The dataacquisition and processing was practicable.