triple point

noun

Physics.

1. the particular temperature and pressure at which the solid, liquid, and gaseous phases of a given substance are all at equilibrium with one another.

triple point

noun

1. chem the temperature and pressure at which the three phases of a substance are in equilibrium. The triple point of water, 273.16 K at a pressure of 611.2 Pa, is the basis of the definition of the kelvin

triple point

1. The temperature and pressure at which a substance can exist in equilibrium in the liquid, solid, and gaseous states. The triple point of pure water is at 0.01°C (273.16K, 32.01°F) and 4.58 mm (611.2Pa) of mercury and is used to calibrate thermometers.

2. Compare critical point

triple point

1. In physics, the temperature at which all three phases of matter (solid, liquid, and gas) for a given substance can coexist.

The triple point for water is a little above the freezing point, and is used to define temperature scales.

Word History and Origins

Origin of triple point¹

First recorded in 1870–75