The US Department of Energy had a requirement to detect and measure corrosion pitting and cracking on the walls of underground waste storage tanks.

Oceaneering Space Systems were contracted to provide the robotic deployment system, control and analysis software, and they approached TSC to provide an ACFM inspection tool.

A number of new challenges had to be overcome during the development. New software data filtering techniques were developed to enable detection of small pits. Twin energising fields were introduced for the first time to improve differentiation between pits and cracks. Finally, radiation-tolerant electronics were incorporated into the design.