Method of in-tube ultrasonic inspection

A method of in-tube ultrasonic inspection of pipelines is carried out by passing inside the pipeline a scanning pig, emitting ultrasonic probing pulses towards the pipe wall and receiving the reflected ultrasonic pulses. The received pulses are amplified using an amplification factor which is increased depending on the time elapsed from the moment of emitting the probing pulse. The threshold values of the pulse amplitudes are also varied depending on time. Digital values of the pulse amplitudes and the time elapsed from the moment of emitting the probing pulse and corresponding to each value of the amplitude are obtained. The method allows for compensation for the effect of ultrasound attenuation in the material on the amplitudes of the reflected pulses and, in this manner, to increase the accuracy of determining the geometrical parameters of the flaws, a probability of their detection and efficiency of estimation of their danger.