PHASED ARRAY + TOFD
These techniques are used mainly for accurate sizing and register of existing discontinuities in equipment.
They are ultrasound techniques.
Phased-array allows the scanning of aimed region by ultrasonic beams built according to inspection exigency, incidents with various angles and exit points, which make the technique more sensitive (detection) and accurate sizing, than the exam by conventional technique which inspects the aimed region only by angles of 45, 60 and 70o. The inspection results are stored, and ultimate generation great treatment and storage capacity software present the data in A, B, C and S-scan views, which allow for analysis of results during and after inspection, besides register to future follow-up of evolution of discontinuities.
This register is also used to substitute the inspection by radiography according to standards known worldwide, such as Code Case 2235 of ASME.
The TOFD is a technique based on diffracted waves in discontinuities edges. This technique is sensitive and allows accurate sizing of discontinuities.