The Ultrasonic In-line Inspection System of Pipelines Based on Spectrum Estimation on-line

The ultrasonic detection is one of the important ways to inspect the wall-loss defects on-line for oil pipeline. The on-line power spectral estimation what characterized short time serial, higher resolution and anti-noise was a key technology to in-line inspect the pipeline. Based on power spectral estimation on-line, the digital multi-channels ultrasonic inspection system with 20 probes was developed. The system consists of main and sub-structure. Inspection board communicated with embedded computer with PCI bus and the numbers of channel was expended by means of high-speed switch. The ultrasonic echo signal was processed with Burg maximum entropy spectrum estimation on-line. The test shows that the inspection system could inspect the inner and outer defects and is suitable for on-line detection of pipeline corrosion. It will be used widely in practice.