A new type of wheeled intelligent ultrasonic thickness measurement system

In the field of industrial ultrasonic testing, ultrasonic thickness measurement (UTM) is a method of performing non-destructive measurement of the local thickness of a solid element basing on the time taken by the ultrasound wave to return to the surface and it is now regularly utilized in all areas of industrial measurements for its advantage of high penetrating power, high sensitivity and greater accuracy than other non-destructive methods in determining the depth of internal flaws and the thickness of parts with parallel surfaces. Couplants are needed to provide effective transfer of ultrasonic wave energy between transducers and parts being inspected. According to the working characteristic of gas pipe, a wheeled ultrasonic thickness measurement system is developed and a kind of special elastic material is used to realize ultrasonic acoustic coupling. The system consists of wheeled thickness measurement probe, pulser and receiver unit, data analysis and storage unit and the interface circuit. Wheeled thickness measurement probe is composed of thickness measurement wheel, auxiliary support wheel, slip ring, carbon brush device, proximity switch and other major parts. The design of thickness measurement wheel uses conventional piezoelectric ultrasonic probe which is installed on the wheel hub. The wheel hub is casted by special elastic material which can realize ultrasonic acoustic coupling through the tight fitting between the wheel surface and the detected specimen. The auxiliary support wheel casted by polyurethane material is embedded with the metal block. The metal block works together with proximity switch to excite the generation of ultrasonic signal. This paper introduces the working principle and design method of the system.