The demand for mechanised ultrasonic wall thickness measurement is fulfilled with the introduction of the Mapscan.

Mapscan applies a mechanical link between transducer and computer to record the thickness data for each predetermined measurement position. The transducer is scanned manually over the surface and the thickness readings are stored on disk. After the scanning is finished, the data is plotted on a wall thickness map. Each thickness level is colour coded and wall thinning by corrosion or erosion is readily recognised. High reproducibility (within 0.3 mm wall loss) enables accurate monitoring and calculation of corrosion rates. This input is very important to estimate time-to-failure.

Mapscan is applied on vessels, pipework (bends), tank walls etc, for exact documentation of corroded regions. It can be applied in service at temperatures up to 250°C. Corrosion phenomena such as general wall thinning, pitting corrosion, flow accelerated corrosion (FAC), hydrogen induced corrosion (HIC) and hot hydrogen attack have been revealed successfully by Mapscan.
Because of its high accuracy, Mapscan is accepted in lieu of internal visual inspection of vessels. Based on the on stream Mapscan results, off stream inspection interval extension is often accomplished.