A system for measuring an injection process includes a measurement chamber filled with a fluid. An injection valve injects the fluid into the measurement chamber. A piston is arranged in the measurement chamber. A sensor generates a voltage which is a measure of a piston travel. The sensor is connected with an evaluation unit which continuously detects the piston travel in the measurement chamber. A rotary displacement pump arranged in a bypass channel to the measurement chamber is driven dependent on an existing volume difference. A pressure sensor is arranged in the measurement chamber. A heating element and/or a cooling device is/are arranged at the measurement chamber and is/are actuated by a controller so that an amount of energy introduced by the fluid injected by the injection valve and an amount of energy introduced by the heating element and/or the cooling device is substantially constant for every injection.