This is a unique instrument developed for the detection of corrosion damage in hidden regions in pipelines that is used by refineries, power plants, and chemical plants. This instrument has the ability to detect and size relatively small pitting type corrosion of 1 mm located in-between the pipe and the support with out the need for the “lifting” of the pipes. The technique uses guided ultrasonic waves generated on the top side of the pipe that travel to the hidden regions and detects the corrosion damage. This product has been testing in field conditions in BPCL, Mumbai.