Fig. 3 (IMAGE) Osaka University Caption Example of measurement results. (a) Reflection of radio waves at a certain point. Reflected waves from the front surface and the back surface of the lining material are observed, and the thickness is estimated to be 76 mm from the difference. (b) An example of imaging the lining thickness in the circumferential direction of the chimney. Credit Osaka University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.