The inspection of pipelines that contain epoxy, HDPE or cement mortar liners is difficult with conventional MFL and UT pigs. The liners can either be damaged by such pigs or are too thick for the sensors to read the steel thickness through the liner. A new technology for the assessment of the steel host pipe, employing low frequency AC fields is presented which overcomes these restrictions. Results from field trials are presented showing the success of the technology in the Alberta Oil Patch.