This work describes the development of an algorithm that uses ultrasound to evaluate the degree of corrosion in pipeline walls. The developed algorithm was implemented in a dedicated digital circuit that can be embedded in ultrasonic pigs for pipeline corrosion inspection. The algorithm is based on the mathematic model known as matched filter. It also incorporates a peak detection method for the localization of ultrasound echoes, originated from the signal reflections in the pipeline walls. One of the problems is the determination of the signal (and filter) that should be used, but using a signal design approach, a large number of possibilities could be analyzed so that only a few had to be tested in experiments. Finally, the best signals were used to inspect a sample made of a corroded pipeline section, and the results were analyzed. The detection of the first wall showed promising results when compared to the results of a tridimensional inspection of the same walls. It was possible to reconstruct the profile of the internal wall with good likelihood, even in badly corroded areas. The detection of the second wall showed some satisfactory results on low corrosion levels, but showed some problems with high corrosion levels, compromising the direct measurement of the pipeline wall thickness.

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