Advanced Non Destructive Testing for Internal Defects, Abnormalities, Shape & Structure. Non-destructive testing is an inspection procedure used to easily inspect an object for internal defects, etc. Standard candidates for Non- destructive testing comprises of casting, welding, railways, buildings, aircraft, bridges, concrete, underground pipelines, and several sorts of factory equipment. Sigma industrial devices are world-class and recognized as high-performance possession units and are used in our combined Non-destructive testing methods as well as by several system integrator partners located across the country.