The following values are recorded as part of ASTM C127. Most noteworthy the SGequation is. Specific Gravity of gases is normally calculated with reference to air - and defined as the ratio of the density of the gas to the density of the air - at a specified temperature and pressure.
The specific weight also known as the unit weight is the weight per unit volume of a material.
The formula for SG is the density of the material under study divided by the waters density. Specific Gravity fracrho_objectrho H_2O frac12 gmL1 gmL 12. Specific Gravity of gases is normally calculated with reference to air - and defined as the ratio of the density of the gas to the density of the air - at a specified temperature and pressure. Instead there are many some only approximations while others are far more precise.