采用对比试块对三种塑料的声学特性进行试验, 测出各自的纵波声速和衰减值。采用研制的纵波斜角探头进行探头K值和前沿测定, 取得较高精度。通过模拟试块检测试验, 发现缺陷定位准确, 测长精度较好。检测热熔焊接接头时, 优先选用直射纵波法, 当壁厚较薄受检测条件限制时, 也可采用一次反射波进行检测。

Acoustic response of three kinds of plastic was studied by contrast test block, and the respective longitudinal wave velocity and attenuation coefficient μ were measured. The k value and frontier of probe were measured by longitudinal wave angle probe, and it has high precision. It was found that defect location was accurately positioned and its length was rather precisely measured through simulation UT for test block. Direct longitudinal wave method was priority to adopt within detection of hot-melt welding joint. But when the thinness was thinner and with detecting condition limit, primary reflection wave can also be used.