A method for quantitative evaluation of pipe wall thinning using microwaves

This research aims to find nondestructive and noncontact technique to detect the degree of pipe wall thinning. Microwaves, which have high sensitivity and resolution, are expected to be able to detect and evaluate pipe wall thinning. A microwave vector network analyzer to generate microwave signals and a waveguide sensor to transmit and receive were employed in this experiment where the frequency was swept in K-band (18 to 26 GHz). By analyzing the frequency domain response of the signals and extracting the shift of resonance frequency that corresponds to the pipe wall thickness reduction, evaluation of the pipe wall thinning degrees was realized. It was confirmed that the results obtained by this experiment are good agreement with the results obtained by our previous method. It was found that there is a liner relationship between a resonance frequency and wall thinning volumes. Our results demonstrate the importance and plausibility of microwave-based detection technique for remote monitoring wall thinning in metal pipeline in industry. (author)