Refrigerant To Service Station Reservoir (Charging Cylinder Or Reservoir Bottle), Transferring

WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

The work procedure is always to be performed as described in the operating instructions for the Air Conditioning (A/C) service station.
A certain quantity of refrigerant is specified as charge for each air conditioning system. To ensure that neither too much nor too little refrigerant is added (either would reduce the cooling output), the charging cylinder has a scale indicating the weight.
The volume of a refrigerant changes as a function of pressure. The scale must therefore be set according to the pressure in the charging cylinder.

NOTE:

Do not completely drain the reservoir (charging cylinder or bottle) as the liquid column boundary layer cannot be traced in the tube during filling (outside visible range).

WARNING:

Do not overfill. A completely filled reservoir (charging cylinder or bottle) will explode when the temperature rises.