Many industries require a liquid source to be converted into a homogenous vapour. Traditional methods have involved either bubbling a carrier gas through the liquid source whilst precisely controlling the temperature and pressure, or directly introducing the liquid source onto a hot surface or plate. The former is extremely reliable, well-proven and offers high repeatability/reproducibility once the controlled process parameters have reached steady state. It is, however, less suited to applications where step changes in concentration are required, where fast switching on-off is required or where multiple liquid sources need to be introduced through one, single evaporation system. Furthermore, this system requires a large volume of potentially hazardous liquid to be housed in a pressurized (glass) container close to the application – often not ideal in highly populated laboratories. The latter has benefits as a highly simplified system however the temperature required for evaporation is much higher, the energy consumption is extremely high and variable control of flow rate/concentration can only be achieved on long cycle times.