Temperature Dependence of the Surface Tension of Water, Including the Supercooled Region

For the temperature dependence of the surface tension of water, the equation formulated as early as 1976 by The International Association for the Properties of Water and Steam (IAPWS) is the most commonly used. There are reasons for a major revision of the equation. In this paper, we critically analyze existing experimental data, and evaluate attempts to develop an alternative equation to IAPWS standard. We have tested different forms of correlation for the temperature dependence of the surface tension of water. We have decided to use Wegner’s form of the description of the thermophysical properties near the critical point, with fixed theoretical exponents. This correlation well describes the experimental data in the range from 240.88 K to 647.096 K. The estimated uncertainty varies with temperature from 0.1 mN·m−1 (for temperatures below 288.15 K) to 0.2 mN·m−1 for temperatures around 373.15 K.