| 摘要 |
PURPOSE:To facilitate observation of the crack, by a method wherein a plural number of metallic parts of the certain identical length are fixed on the surface of high- temperature member, and a detector of the sound wave conducting interior of the member is connected to the end of the metallic parts. CONSTITUTION:A glass fiber layer 10 for vibration absorption is prepared around a bolt 9 fixing a heat insulator 8 of an object to be inspected (steam turbine, etc.) 1, and a sound wave detector 2 is attached to the end of the bolt 9. The detection signal for sound wave of crack of the object to be inspected is inputted to a recorder through a preamplifier, a band-pass filter to pass a frequency band of 130-300kHz and a main-amplifier. This arrangement facilitates the measurement of cracks. |
