At the ILK Dresden a humidification system was developed and manufactured which is especially suitable for research facilities where very low dew point temperatures have to be adjusted and at the same time a high gas purity has to be guaranteed. The core component is a PermaPure^® humidifier with Nafion^® moisture exchange. The humidification system precisely controls the dew point via a bypass mixing with dry gas and also takes over the automatic filling of evacuated containers. The control system is optimised to prevent recondensation. Humidification can be controlled from any plant system via an interface. Table 1 shows the technical data of a humidification system for the humidification of synthetic air realized for the KIT in Karlsruhe. The system can be adapted for other applications, and all parameters can be adjusted to the respective requirements.