Volumetric Nondestructive Examination : Examination for internal material defects by method such as radiography and/or ultrasonic testing. (Spec 6A, Spec 16A)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}