Design Of Digital Ultrasonic Testing Device

Ultrasonic inspection is a very important composition of NDT(Non-destructive testing), which has been widely used in the field of modern metallurgy. Ultrasonic inspection is the most important test link before the steel transfer to the customers. On the basis of low-cost, Ultrasonic inspection played a irreplaceable role in the quickly and accurately judging the defective in the rolling fields.In this paper, the status and the development of ultrasonic flaw detection technique at home and abroad are introduced and the basic principle of ultrasonic flaw detection is presented. Briefly described the basic principles of ultrasonic testing, for rapid non-destructive inspection of the plate, proposed the method of inspection.In the design, the hardware system of digital ultrasonic testing device consist of power module, ultrasonic transmitter circuit, isolation circuit between transmitter circuit and control circuit, echo signal conditioning circuit, system control circuit and USB communication module.The software system is composed of main MCU software, slave MCU software, host computer software system. Among them, the main MCU responsible for the issuance of ultrasonic signals, LCD panel control, echo signal amplification gain control, detection channel selection and data exchange with host computer; the slave MCU responsible for collection echo signal, uploading the echo data to the host computer; the host computer system is designed based on VC6.0environment. The system can realize real-time data acquisition、display of ultrasonic wave and effective assessment.In this paper, the basic principle of wavelet transform is iscussesed, several common wavelets are cited, and we discuss how to select the wavelet and how to transform the wavelet, the results of the wavelet transform is obtained, The meaning of wavelet transform to the ultrasonic testing explained is explained.In the last, experimental verification is done using exist conditions.By the detection test block and calculation of experimental data, the system can determine the defect location and defect size accurately. The Experimental data meet the requirements of ultrasonic inspection system basically.When designed the systems, modularization designing is used to increase system maintainability. The system has large LCD, touch keyboard and the Chinese operation interface to make operation easier. Though the system has such strong functions, it still keeps properties of small size, simple structure and low cost.