Other methods

What is NDT? 

NDT is widely used in sorting components for uniformity of size, material, heat treatment and for sorting batches of basic engineering material metal stock (different steel and aluminium alloys).

NDT is also used for foreign body detection in bulk materials and in encapsulated products.
There is a wide range of specialised NDT methods which have found limited use in specific fields. These include microwave methods, proton absorption, positron annihilation, neutron scatter, etc. Generally, these are laboratory techniques, not yet commercially developed.