| 摘要 |
PURPOSE:To decide exfoliation of wall face tile in a short time by deciding a tile to be sound when a crest factor obtained from the hitting sound with hummer is higher than a set level or when the crest factor is lower than the set level but the difference between the expected frequency obtained from the hitting sound and the expected frequency of sound tile is lower than another set level otherwise deciding the tile to be exfoliated. CONSTITUTION:A tile to be inspected is hit with a hummer, for example, based on a command from a computor and the hitting sound is detected in order to calculate a crest factor Cf. It is then compared with a predetermined value M based on the crest factor and a decision is made that the tile is sound if Cf>=M. If Cf<M, it is regarded as a pseudo exfoliated state and an expected frequency Rf2 for next decision is calculated. The difference between the Rf2 and a predetermined expected frequency Rf1 for sound tile is then compared with an experimentally determined value DELTAf. Rf2-Rf1<DELTAf means a sound tile and Rf2-Rf1>=DELTAf means an exfoliated tile. This method requires a small amount of calculation and the processing time of computor can be shortened. |
