The combination of degree symbol ° followed by an uppercase letter F is the conventional symbol for the Fahrenheit temperature scale. A number followed by this symbol (and separated from it with a space) denotes a specific temperature point ("e.g." "Gallium melts at 85.5763 °F"), a difference between temperatures ("e.g." "The output of the heat exchanger experiences an increase of 72 °F") or an uncertainty in temperature ("e.g." "Our standard uncertainty is ±5 °F"). The symbol for the Celsius scale also uses the degree symbol but with an uppercase letter C ("°C"), while the symbol for the Kelvin scale is just an uppercase letter K ("K"). The numerical value of a temperature difference or temperature interval is the same when expressed in either degrees Celsius or in kelvin.