| 摘要 |
ultrasonic inspection of articles. SUBSTANCE: increased accuracy of determination of thickness of articles with single way of access whose thickness is very small is achieved thanks to installation of ultrasonic piezoelectric converter at point of determination of thickness, to feeding of pulses of ultrasonic oscillations and to reception of ultrasonic oscillations reflected from bottom surface of article. Pulses of ultrasonic oscillations are fed and ultrasonic vibrations reflected from bottom surface of article are received in sequence with the aid of separating-integrating piezoelectric converters from set of separating-integrating converters with specified values of thickness of acoustic screens d1, d2,..., dn-1, dn, where n is number of converters, n>1 is specified number of converters found in corresponding dependence with tested thickness of article. Per each n-th separating-integrating piezoelectric converter , where hn is tested thickness of article per n-th separating-integrating piezoelectric converter; Cnl1 is velocity of propagation of longitudinal ultrasonic waves in prism of n-th separating- integrating piezoelectric converter; C12 is velocity of propagation of longitudinal ultrasonic waves in material of which tested article is made; dn is thickness of acoustic screen of n-th separating-integrating piezoelectric converter. Then intensity or amplitude of ultrasonic oscillations reflected from bottom surface of tested article is measured per each separating-integrating piezoelectric converter from set of separating-integrating piezoelectric converters, dependence of intensity or amplitude of ultrasonic oscillations reflected from bottom surface of tested article on hn is constructed and thickness of tested article is determined by point of sudden change of intensity or amplitude in constructed dependence. EFFECT: increased accuracy of determination of thickness of article. 2 dwg |
