Using the coherence coefficient to improve the image quality of reflectors during ultrasonic testing by the TOFD method

It is difficult to prove from the CFA or FAR image of a vertically oriented crack that two blocks correspond to the edges of the crack, and not two point reflectors. The idea of clarifying the type of defect - by analogy with the TOFD method – is to analyze the phases of the image highlights.

It is difficult to perform such an analysis manually, as shown in the figure below.

The AUGUR Analysis software includes an algorithm that, when the operator selects two indications, calculates the average phase difference in the glare maxima zone and outputs this difference.

An example of measuring the phase difference at the upper and lower edges of the crack model, the phase difference is close to 180°

An example of measuring the phase difference in two volumetric defects, the phase difference is close to 0°

This tool can be used as an auxiliary in determining the type of defect detected.

The video below shows an example of the AUGUR Analysis program.