Couplant 2 : The couplant, a liquid such as water, oil glycerin, etc., capable of conducting ultrasonic vibrations from the transducer to the material being tested shall be used. (RP 2X)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}