Abstract
The General Assembly of the International Association for the Properties of Steam (IAPS), meeting at the 10th International Conference on the Properties of Steam in Moscow in September 1984, adopted new formulations for the thermodynamic properties of fluid H2O and D2O. The new formulations have been designated as the IAPS Formulation 1984 for the Thermodynamic Properties of Ordinary Water Substance for Scientific and General Use and the IAPS Formulation 1984 for the Thermodynamic Properties of Heavy Water Substance. In this paper we present and discuss these new formulations.