Microwave Detection of Machined Notches in Stainless Steel with Rough Surface

Microwave near-field techniques, employing open-ended rectangular waveguide probes, have shown great potential for detecting tight surface cracks in metals as well as estimating their dimensions. However, the utility of these techniques has yet to be examined when detecting cracks in rough surfaces. In this paper, the results of using these probes, at different microwave frequencies, when detecting several machined notches in a steel specimen with a rough surface are presented