Celsius - Coexistence of Kelvin and Celsius Scales

Coexistence of Kelvin and Celsius Scales

In science and in engineering, the Celsius scale and the Kelvin scale are often used in combination in close contexts, e.g., "...a measured value was 0.01023 °C with an uncertainty of 70 µK...". This practice is permissible because the magnitude of the degree Celsius is equal to that of the kelvin.

Notwithstanding the official endorsement provided by decision #3 of Resolution 3 of the 13th CGPM, which stated "a temperature interval may also be expressed in degrees Celsius", the practice of simultaneously using both °C and K remains widespread throughout the scientific world as the use of SI prefixed forms of the degree Celsius (such as "µ°C" or "microdegrees Celsius") to express a temperature interval has not been well-adopted.