ULTRASONIC PROBE USING CONSTANT PHASE METHOD IN NON CONTACT AIR COUPLED ULTRASONIC TESTING TECHNOLOGY

PROBLEM TO BE SOLVED: To improve S/N while using a constant incident angle focusing method.SOLUTION: An ultrasonic probe uses a constant phase method in a non contact air coupled ultrasonic testing technology, and comprises: a housing including an aperture facing a pipe as an inspected pipe; and multiple oscillators that are held in the housing and output pulsed ultrasound to the pipe. The oscillators are individually arrayed so as to position their centers A, B, C and K on a virtual surface L at a predetermined distance from a center D of the pipe and to focus the ultrasound output at a position O which is on an arbitrarily-determined radial line r1 of the pipe and is at the predetermined distance from the center D of the pipe. The ultrasonic probe configured as above can improve S/N with its configuration of applying a constant phase focusing method with determining an incident angle i as constant and determining a phase as constant (corresponding to constant distances AE=BF=CG=KH), while using a conventional constant incident angle focusing method.