| 摘要 |
PROBLEM TO BE SOLVED: To dispense with work such that judging reference data is preliminary inputted by experiment at each time when the peeling of a wall surface is diagnosed and the diagnose the peeling of the wall surface with high reliability. SOLUTION: The striking sound signal from a strinking sound sensor 2 is amplified by an amplifier 3 and sent to an A/D converter 4 to be converted to a digital signal which is, in turn, inputted to an operational processor 5. The operational processor 5 is equipped with a DSP 51 analyzing the frequency of the digital signal and a memory 52 and the striking sounds obtained by striking the healthy part of a field wall space a definite number of times are analyzed in frequency and the analyzed results are averaged to obtain reference spectrum data which is, in turn, stored in the memory 5. The judgment of peeling is performed by the comparison of the deviation between the spectrum peak frequency of individual spectrum data to be judged and the spectrum peak frequency of the reference spectrum data with the sum total of the primary moment of individual spectrum data and a spectrum. |
