METHOD FOR MIRROR-SHADOW ULTRASONIC TESTING WITH AN ADAPTIVE THRESHOLD LEVEL Russian patent published in 2023 - IPC G01N29/04 

FIELD: ultrasonic testing.

SUBSTANCE: invention is intended to form an adaptive threshold level for detecting defects during ultrasonic testing of extended products, in particular, railway rails and other products with plane-parallel surfaces (rolled metal, tee elements, etc.). The substance of the invention lies in the fact that with the help of an electroacoustic transducer with a given step, probing ultrasonic signals are emitted into the product, bottom signals reflected from the opposite surface of the product are received, their amplitudes are estimated, the electroacoustic transducer is moved along the surface of the product, an envelope of the amplitudes of the bottom signals is formed, based on the current values of amplitudes of bottom signals, correct the threshold level of detection of defects, while forming an analysis window sliding synchronously with the movement of the electroacoustic transducer, in the specified window determine the distribution of amplitudes of bottom signals, the resulting distribution determines the fluctuation level of amplitudes, below which there is a given proportion of signals with the lowest amplitudes, taking into account the bottom signals, the amplitudes of which are higher than the fluctuation level, the base level is determined and the threshold level for detecting defects is set relative to it.

EFFECT: increasing the reliability and reliability of ultrasonic testing of long products in difficult conditions.

1 cl, 3 dwg