calorific value (gross) #02058OIML 1. In the following parts of this Recommendation, calorific value is used for gross calorific value. 2. The condensation enthalpy and combustion enthalpy depend directly upon the temperature and pressure; consequently the energy at base conditions is considered. 3. The calorific value should be determined on a mass or volumetric basis. 4. (adapted from ISO 6976)