Measuring system for the wall thickness of pipe based on ultrasonic multisensor

To solve the problem of deficiency detecting, it is necessary to detect the wall thickness of pipe rapidly, continuously, successively and accurately. For that purpose, this paper introduces a dynamic testing facility for on-line high-speed inspection of underground oil or gas transportation pipelines. The facility consists of a high-energy multi-channel ultrasonic focusing probe, a water-spraying coupler and a computer testing software developed in VC++ 6.0. Compared with the traditional testing methods, the system can not only probe the wall thickness of rigid tube material continuously by using multi-channel ultrasonic probes, but with the affiliated computer testing software it can also display curves of thickness in multi-graphs and give out warning when it exceeds the standard range. Furthermore the data can be stored and searched conveniently. Experiment has indicated many advantages in the equipment. Firstly, its detecting speed reaches 25 m/min. Secondly, its testing accuracy is high. The accuracy is plusmn0.1 mm, and the pipeline wall that can be tested by the equipment is more than 10% of the thickness and the pipeline ektexine that can be tested is more than 12.5% of the thickness. Especially, the experimental results conform to requirement of the latest API-5CT standards. Thirdly, it has credible detecting capability.