What is the impact of a different reference temperature?

The reference conditions in most units is 0°C and 1013.25 mbar. (Normalized flow). If you want to calculate the difference between 0°C and 20°C, e.g., the formula is as follows:
(flow at 0°C /273.15)*293.15

Example:
100 ln/273.15*293.15 = 107,32 ln
This corresponds to a correction of 0.366 % per degree Celsius