抄録
We have evaluated the possibility of defect detection on the acrylic plate, cylinder solid and cylinder by using the surface wave of non-contact air coupled ultrasound. In the case of the surface defect of the acrylic plate and cylinder solid in outer diameter 50mm, acoustic pressure became low when the defect width with the defect depth of 1mm and 2mm became large to 2mm. In the case of the inner surface defect of the acrylic cylinder which outer diameter was 50mm and inner diameter was 43mm, acoustic pressure was the lowest when the depth to the defect was 0.5mm, and it was able to detect the defect until depth 2.5mm.
