Sensitive gas sensors are widely used in industrial and consumer applications for gas analysis. Here, a critical point is the encapsulation of the sensitive sensor material to protect it from degradation. In this paper, polyvinylidene fluoride (PVDF) is discussed as a membrane material. The polymer is characterised in terms of its permeation properties towards carbon dioxide. For the gas permeation measurement, a self-developed experimental setup was adapted and tested to the single membrane measurement.