Design Of Dual Channel Ultrasonic Testing System Based On HCS12X

As one of the main means of nondestructive testing, ultrasonic testing technology has been widely applied to various fields at home and abroad. Ultrasonic testing system is the main carrier of ultrasonic testing technology, and it has a lot of advantages:strong penetrating power, high precision, low cost, high speed, flexible operation, etc. But it has some disadvantages, such as large volume, single function and so on. Therefore, it means a lot that develop a type of ultrasonic testing system which is multi-functional and easy to carry in the research of ultrasonic testing technology.In view of the existing problems at the ultrasonic testing systems, this paper proposes a new solution and develops a set of ultrasonic testing system with dual channel detectio’n mode. Freescale MC9S12XS128is used as a MCU in this system to make the whole circuits work coordinately and orderly. One channel of the system uses single crystal probe to transmit and receive ultrasonic signals, and it can be used for echo detection, such as defects judgment, thickness measurement and so on; Another channel uses two probes, one of which transmits ultrasonic signals and another receives echo signals, and it can be used for pulse transmission detection, such as melon and fruits detection. In order to match different frequency probes and make transmission power adjustable, transmitting circuits of the system adopt untuned incentive mode. Damped limiter, high-frequency amplification and noise filtering of weak echo signals, which makes output signals to satisfy the range of subsequent acquisition circuit. For data acquisition circuit, this paper adopts the way of a time-sharing access and completes acquisition and storage of2.5MHz echo signal. In addition, Serial communication circuit and LCD module are designed to communicate between MCU and PC and display some instructions. The system has many advantages such as transmitting power being adjustable, suitable for different testing objects, easy to carry and so on.Finally, every function of hardware circuit is realized through programming software, and the ultrasonic testing system developed was validated by the experiment. The results show that each index of ultrasonic testing system meet requirements of the design.