METHOD OF EVALUATING DEFECT IN RAIL HEAD Russian patent published in 2012 - IPC G01N29/04 

FIELD: physics.

SUBSTANCE: pairs of mutually directed electroacoustic transducers are placed in the vicinity of the presumed defect on opposite surfaces of a rail head; all pairs of electroacoustic transducers are moved on said surfaces of the rail head; the rail head is probed, for which in each pair, ultrasonic signals are emitted by one and received by the other electroacoustic transducer; boundary lines of the defect are determined by a shadow method; said lines are jointly analysed and the size and location of the defect is determined; pairs of electroacoustic transducers of the first group are placed on lateral surfaces of the rail head, and each pair of electroacoustic transducers is provided with a second pair of electroacoustic transducers such that the probing lines of the first and second pairs are not parallel, wherein movements of the pairs of electroacoustic transducers are made with a step which ensures the required resolution when searching for the defect; electroacoustic transducers of the second group of pairs are placed on the roll surface and the surface under the rail head, wherein electroacoustic transducers placed on the surface under the rail head are emitting transducers; when probing with the second group, the propagation time of the ultrasonic signal is measured and the thickness of the rail head is calculated on the probing line, and when detecting the defect, the signal reflected from the signal is received, its propagation time is measured and the depth of the defect is calculated and its hazard level is determined.

EFFECT: highly reliable detection of defects of arbitrary orientation, and determination of the size and position thereof.

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