| 摘要 |
PURPOSE:To detect the presence of an adhesive layer even if thin by irradiating a resin molded product with ultrasonic wave to calculate the waveforms of the reflected waves of the inside, intermediate and outside layers thereof and discriminating the adhesive layer and the thickness thereof from the small displacement waveform of the outside layer and the peak waveform of the intermediate layer. CONSTITUTION:A probe 40 radiates a tank 10 with ultrasonic waves to receive the reflected waves from boundary surfaces. The reflected wave signal from the probe is processed by an ultrasonic control part 41a to project waveforms on an oscillograph 42. The waveforms are obtained by processing the signal obtained from the probe 40 on the basis of the relation between the propagation speed of ultrasonic waves in a substance such as a resin and the reflectivity at the boundary surface of mutual different substances. The waveforms of the reflected waves of an intermediate layer 20 and adhesive layers 31, 32 among the irradiated ultrasonic waves are stored to search the peak point of the boundary surface on the inner surface side of the intermediate layer 20 and the next peak point on the internal side thereof to calculate the distance between the peak points. When the distance is a reference value or more, the presence of inside adhesive layers 31, 32 is outputted and, when the distance is the reference value or less, the distance is outputted from the propagation speed between the peak points. |
