| 摘要 |
PURPOSE:To obtain an inspection method of a hook for crane at a low cost, safety, and without causing any personal error to be generated in inspection result. CONSTITUTION:A probe 5 which transmits and then receives ultrasonic wave is mounted to an upper portion of a hook screw portion 4 for transmitting ultrasonic wave, a flaw-detecting echo which is reflected from its damaged portion according to the degree of damage of the screw portion 4 is received, and this flaw-detecting echo is converted to an electrical signal and then is transmitted to an inspeciton recorder 6. The inspection recorder 6 displays pulses 9 with a height corresponding to the electrical signal, sets a threshold 10 for the inspection whethre the hook is acceptable or not to a pulse display portion 8, and then determines to be defective when a pulse exceeding the threshold 10 is detected among the pulses 9 which are displayed on the pulse display portion 8. |
