Calculation for the Blind Zone of TOFD Testing Technology and its Characteristic Analysis

The parameter tp (time width of through wave) of TOFD testing technique was discussed. The calculation formula was modified with the comparison testing results. Blind zone was analyzed and calculated on the characteristics of the upper and bottom surface, and the effective factors were concluded. Furthermore, the effect caused by the welding groove type and configuration on the blind zone was investigated, and the blind zone simulation was conducted in the computer by software CIVA.