A method using ultrasonic devices for on-line measurement of oil coiled tubing was proposed. The
principle of ultrasonic testing was analyzed. Then, the structure of the system consisting of mechanical
system, coupling system, measuring system, control system and system software was determinated.
Based on the analysis of technology requirement, measuring technique in which the coiled tubing did
not rotate and the probe was static was chosen. The ultrasonic testing probes were triggered in turn.
After signal sampling, digital filtering and A / D conversion signal processing, the received echo
signals were sent to computer. Through analyzing and accounting, the test results were obtained. Based
on VC++.net, A-type ultrasonic and C-type ultrasonic display software and the inspection data
processing software were developed. Using Windows programming technology, the software structure
and function library were totally open. Therefore, secondary development can be carried out
conveniently. Based on the experimental studies, coiled tubing's ultrasonic testing system is developed.
The testing results show that the system has specific advantages such as high-adaptation, highefficiency,
high- stability, high reliability and can meet the need of the users. The ultrasonic testing
technologies proposed in this paper can be applied extensively to other tubes.