| 摘要 |
<p>An ultrasonic inspection apparatus comprising a large number of array oscillators (101 ∩ 10n) in a columnar shape. The oscillators are excited sequentially to generate a sequence of ultrasonic beams to scan an object of inspection. The reflection from the object is analyzed to inspect the surface condition of the object and the existence of any fault inside it. Before an inspection, ultrasonic scanning of a reference material having a uniform quality and free from any defects is performed in order to collect the reference data for each ultrasonic beam (each channel). Correction values are prepared on the basis of these reference data and the reception signals obtained by the ultrasonic scanning of the object are corrected by use of these correction values. One correction means determines the ratio of the mean value of the reference value to the reference value of the channel for each channel, multiplies the reception signal of the same channel by the ratio as the correction value and uses the product as the data to be displayed on a display unit (21). Another correction means determines a damping ratio to the reference value of each channel so that the reference value of each channel becomes a minimum value or a predetermined value below the minimum value, and the reception signal of the same channel is damped by a sensitivity leveling circuit (31) using the damping ratio. Variance of sensitivity between the channels can be eliminated by these correction means.</p> |
