Temperature compensation
Since the implementation of the European MID directive, fuel pumps with temperature compensation have also been permitted in Germany. During the refueling process, these adjust the displayed delivery quantity according to the calculated expansion at an assumed ambient temperature of 15 °C. In temperate latitudes, the ground temperature is rarely above 15 °C all year round, so that through temperature compensation i. d. Usually a higher quantity than the actual delivery quantity is displayed and billed.
The correction factor for carburetor fuels is approximately one per mille per Kelvin, which means that e.g. B. if 100 liters of 9 °C cold fuel were delivered, 100,6 liters would be billed. Temperature-compensated fuel pumps can be recognized by the fact that on the display board and invoice the unit for the dispensed quantity is not “liter” or “l”, but “liter at 15 °C”.
For the operator, temperature-compensated fuel pumps have the advantage that delivery to the customer takes place under the same conditions as delivery (this is generally temperature-compensated), which reduces the “waste” that would otherwise inevitably occur. For the customer, temperature-compensated fuel pumps have the disadvantage that they do not underestimate the amount of fuel dispensed compared to a conventional pump that measures the actual delivery temperature.
Source: Wikipedia