It has been shown that enhanced penetration of fluorescent liquid into microcracks due t ultrasonic capillary effect improves the quality of testing and creates the basis for the development of new penetrants. Maximal effect of ultrasound on penetration of liquids into microcracks is achieved at vibration amplitude of the radiating surface in the range 7-15 Ath, where Ath is the vibration amplitude of the ultrasound source corresponding to the cavitation threshold in a working liquid.
