Research On Application Of Multi-channel Roundly Detecting Wall-thickness Of The Steel Pipe

Ultrasonic thickness measurement is one of the main technical of non-destructive testing. Recently, with the rapid development of the computer and electronic technology, the research on ultrasonic thickness measurement system towards the development of digital, intelligent direction, which have a wide range of applications in the materials industries, petrochemical, machinery manufacturing areas.In order to solve pressing technical problems that automatic roundly detecting total length wall-thickness of the steel pipe, first of all, the paper introduced the basic physics of ultrasound, analyzed the instantaneous reflection and transmission of ultrasound normal incidence on the multilayer planar, and referred to array of multi focusing probes rotational measurement on steel pipe. Based on the focusing probe measurement theories of wall thickness and analyzed the relationship between focusing probe' s focal length, chip size and focusing sound field, the focusing probe which was appropriate for steel pipe constituted arrayed system. At the same time, the system increased the scanning points, and expanded the coverage area of the probe.By virtue of the application involving with focused ultrasound multi-probe principle of ultrasonic measurement, and the combinations with extra high voltage circuit, special signal processing circuit, and intelligent technologies of FPGA digital signal acquisition, logical processing, control technique and integrating array probe covering the steel pipe, some difficult points and problems in these academic researche finally were resolved effectively.In the end, it is necessary to set up visualizatical detect interface for real-time detecting and reflecting the information of steel pipe' s wall-thickness. Based on the Windows 2000 operating system and used Visual C++7.0 software that developed graphical user interface, providing a simple man-machine interface easy to learn, achieve fully automatic detection, to avoid people's emotional impact on the test results. The experimental results show that the detecting system is accurate, reliable and rapid to carry out the full-assignment towards steel pipe, meanwhile it also submits to API (American Petroleum Institute) standards which are applied in practical manufactures.