Which scale is used to measure absolute temperature?

The Kelvin scale is used to measure absolute temperature, which is significant in scientific contexts, particularly in thermodynamics. Absolute temperature refers to a theoretical temperature measurement relative to absolute zero, the point where all molecular motion stops, defined as 0 Kelvin. The Kelvin scale is an absolute scale, meaning it starts from this absolute zero and measures temperature in increments equivalent to those of the Celsius scale, where one Kelvin is equivalent to one degree Celsius.

By contrast, the Celsius and Fahrenheit scales are relative temperature scales based on specific points—freezing and boiling of water for Celsius, and specific temperature points defined by a mixture of ice and salt for Fahrenheit. These scales do not start from an absolute zero but instead from these reference points, making them unsuitable for measuring absolute temperature. The Rankine scale, while also an absolute scale similar to Kelvin, is less commonly used in scientific contexts and is primarily seen in certain engineering applications. Thus, the Kelvin scale stands out as the primary measure for absolute temperature in scientific disciplines.