Research On Digital Module Of Ultrasonic Testing

Digital ultrasonic non-destructive testing (UT) technology has become a main modern NDT method, and is more and more favored recently. A digital ultrasonic testing system was introduced in this dissertation, which is based on the lap-top computer and traditional ultrasonic testing instrument. A digital module of UT is developed by taking full advantage of the software and hardware resource of the computers, aiming at testing of weld defects in the gas pipeline construction project.The analog signals of ultrasonic fault detector are digitalized successfully. The digital module of UT is developed by using micro-chip processor and large-capacity memory data acquisition system. The acquisition data is stored in the high-speed cache directed by the clock signal. The data is read out by the micro-chip processor and transmitted to the upper computer by the serial port. The micro-chip processor is Intel 8031 and the A/D converter is ADC max 1444. The monitoring program is programmed by C developing tool-KeilC5 1 , which is an integrated developing environment and easy to use, and compact the code compiled is. KeilCSl is an ideal substitute for assembly language for developing micro-chip processor monitoring program.An application program is developed successfully, which can transmit the data from the data acquisition system to the upper machine by serial communication. The application is developed by Visual C++6.0 and composed of main window, serial communication module, curve displaying module and digital signal processing module. The three function module are packaged in DLL respectively. This construction is convenient to maintain and upgrade. The application can run in the operating system of Windows9x, Win Me and Windows 2000. The menu command is adopted in the software. The ratio of signal-to-noise is raised and the system reliability is improved by using the digital signal processing technology.