Specific Gravity 20 : The ratio of the weight of a substance to the weight of an equal volume of a standard substance. Water is the standard for liquids and air is the stand for gases. (GL)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}