| 摘要 |
PURPOSE:To enable to inspect simply and nondestructively at any time desired, the coil located in a place impossible to approach by making it to have the construction to enable to inspect by the ultrasonic waves by burying the ultrasonic waves oscillator in an insulating layer. CONSTITUTION:The ultrasonic waves oscillator 4 is buried in the surface layer of the insulating layer 2 of the coil 3 in which the layer 2 is formed by winding insulating material such as mica on the conductive body 1. Said oscillator 4 is provided with the ultrasonic wave transmission and reception apparatus 5 transmitting and receiving the ultrasonic waves and recording device 6 and also, synchroscope 7 observing recorded waveforms. The ultrasonic waves of AC waveform is transmitted and received to the oscillator 4 by the apparatus 5 and is recorded in the device 6. When the waveform is observed via the synchroscope 7, the phase of the reflected waveform 10 between the layer 2 having a sound insulating part and body 1 is reversed to the phase of the reflected waveform 12 having the exfoliated part 11 between the layer 2 and body 1. Accordingly, the coil being impossible to approach is simply and nondestructively inspected at an optional time, with such constitution. |
