2015. Vol.18. No. 3, pp. 45-46
Effective Method of Correction of Acoustic Loses in a Contact Layer at Ultrasonic Flaw Detection
Within a frequency rate of 1.8–5 MHz and an incident angle rate of 35–70° the correlation between sensor readings and acoustic losses in a contact layer has been ascertained; a general dependence for them has been obtained, a heuristic equation has been derived and nomograms for piezoelectric transducers of different manufacturers on the sample basis of 123 measurements have been plotted.
As a result the new technique of ultrasonic flaw detection has been developed that includes: estimation of tested object real surface roughness with the DShV sensor, flaw detector sensitivity adjustment using a sample with a smooth surface, a gain factor correction by the value taken from a nomogram or calculated on the formula basis. Equivalent defect area should also be measured according to the algorithm described. This technique on principle increases repeatability and reliability of flaw detection results.
Keywords: ultrasonic flaw detection; acoustic loss correction; contact layer
- Shcherbinskii V. G. Influence of acoustic transparency of surface contact layer on flaw detectability in ultrasonic testing. Insight. 1998. V. 40. No. 6. P. 411–417.
- Shcherbinskii V. G. Ustroystvo dlya ultrazvukovogo kontrolya sherokhovatosti poverkhnosti izdeliya [Appliance for ultrasonic roughness measurement]. Patent RF, no. 94693. Bull. Izobreteniy [Bulletin of Inventions], 2010, no. 15 (in Russ.).