Ratio of Specific Heats : Thermodynamic comparison (k = cp/cv) of the ratio of a specific heat (k) at a constant pressure (cp) to a specific heat at a constant volume (cv). The ratio range for most gasses is 1.2 to 1.4
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}