In the automotive industry piston dosing systems are used for glueing car windscreens and windows. These dosing systems supply the highviscosity glue to the application gun in an exactly controllable way. The volumetric flow control required for this purpose is achieved by means of a suitable long-stroke sensor in the hydraulic cylinder. The travel signal of the piston is differentiated, and the speed signal deducted from this is supplied to the closed-loop control circuit. The filling volume is determined through the position of the piston.