The present invention relates to a device for measuring the volume flow rates processes which are time-resolved. The flow amount of process among other things, the flow course of the injection process in an internal combustion engine, the said apparatus, translational capacity difference pickup (4,5,6) are provided. The translational capacitive difference pickup (4,5,6) basically, the measurement chamber (4) arranged piston into (5) and a detection device for picking up the displacement of the piston (5) (6) It consists, detection device (6) is connected to the evaluation unit (12). In the measuring chamber (4) in the present invention, in addition to the pressure sensor of the detection device to pick up the displacement of the piston (6) (14) also is arranged, by the pressure sensor (14), the displacement of the piston signal of the detection device (6) corresponding to is improved. To do this, the compressibility of the fluid in the measuring chamber (4) inside are considered when calculating the injection quantity. By this device, it represents a flow process with a high time resolution, the total amount nor will be able to display and evaluate precise process.