Definition of Non-destructive testing:
Quality control method that does not damage or destroy the material or product being tested. Performed on a finished item instead of on a material sample, it uses infrared radiation, radiography, ultrasound, x-rays, and other techniques to detect fatigue effects, structural flaws, and other such defects. Used also in authentication of art objects and paintings. See also destructive testing.
Meaning of Non-destructive testing & Non-destructive testing Definition