METHOD OF MEASURING PROPAGATION VELOCITY CHANGE OF HEAD ULTRASONIC WAVE AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC G01H5/00 G01N29/34 

FIELD: physics.

SUBSTANCE: method of measuring the propagation velocity change of the head ultrasonic wave involves the initiation and reception of ultrasonic pulses held on the product, the digitization of pulses, the entry in the computer, and the definition of the time intervals between the pulses. The head acoustic wave is excited by laser radiation, a laser spot is formed and its associated excited acoustic beam, a generated acoustic beam, is directed from the generator at an angle β close to the first critical one, through the sound line to the product surface, and then is received at an angle - β through two sound lines spaced apart from each other and the generator by a distance L. The sound lines are made in the form of prisms made of a synthetic polymer of methyl methacrylate. The device implementing the proposed method, contains a laser pulse generator, an optical-acoustic transducer, a product, points of removing the ultrasonic pulses from the first and the second piezo-receiver, the first ADC block, a computer, the second ADC block, a thin immersion layer of coupling fluid, acoustic lines.

EFFECT: increasing the resolving power and the accuracy of measuring the propagation velocity change of the head ultrasonic wave.

2 cl, 2 dwg