Design Of Ultrasonic Wall Thickness Meter Based On ARM

Nowadays the safety evaluation of the buildings is mainly based on thethickness of the Cast-in-place floors and the walls. More and more attention hasbeen paid by the departments concerned in our country, and all the supervisionand inspection departments on the engineering quality are also focused on thethickness of the walls and test technology on floor without damage. But thetraditional equipment for testing thickness of the walls have many disadvantages,such as low accuracy, big volume, high cost and power, and its interface is alsonot friendly. So it is not suitable to used widely on construction and other relatedfields.Based on plenty of reading articles on the pulse reflecting method,transmission method and resonance ultrasonic thickness testing theory, we adoptthe pulse reflecting method to design. Combined PSF-1440TR of sending andreceiving from one probe which is produced by the Olympus company and thetechnology of calibration function, we put forward the overall design of thissystem and the whole block diagram of the ultrasonic testing system. We adoptthe new low power processor STM32F103whose core is ARM Cortex-M3as thecore processor, and it can realize control and display and communication of thesignals. On hardware, we complete the design of the CPU control circuit,ultrasonic front launch circuit, receiving circuit, amplification filter circuit anddisplay interface circuit, of which launch circuit is made up of the high voltagepower, emitter follower, PWM synchronized single, pulse amplification circuitand probe. ST7565PLCD is chosen to display circuit choose, whichcommunicates with the main computer by SPI. On software, we complete theprogram design of the calibration function, measuring process procedure, launchprocedure and all function modules. Through the software and hardware designed,we finally achieve the thickness and defect testing on the concrete wall. This instrument has practical significance.Single probe ultrasonic measuring instrument on testing the thickness ofconcrete wall which is based on ultrasonic pulse multiple reflecting methoddesigned in this paper, can measure the thickness from8to110centimeter. It setstwo modes, which are thick and thin mode, and its accuracy can receive1mm. Itcan also be applied on walls which are comprised by all kinds of reinforcedconcrete, and it has a all-sided function and a strong practical. So it has a goodperformance on quality testing of the concrete and the improvement on safety ofthe buildings.