Many small laboratory applications such as fuel cell tests, membrane tests, or annealing furnaces, need a moderate flow of a gas of a certain composition, delivered at near atmospheric pressure. In some cases the gas needs to be dry, in some cases humidity does not mater, and in some cases the gas needs to be humidified.

Inadvertent closure or clogging of the gas flow in the application may lead to risk of overpressure buildup. This is especially dangerous in the case of use of homemade humidifiers based on glass bottle bubblers. Professional and commercial fuel cell test stations with humidifiers take care of these things, but are often excessively expensive and sometimes provides too coarse control of overpressure and of pressure differences between cell chambers in fuel cells and other small and sensitive membrane test setups.    

The "Probble" provides a simple, safe and inexpensive alternative and solution. It makes use of one volume of liquid water for both humidification, overpressure safeguarding, pressure difference control, and flow visualisation. It utilises materials and construction that make the device simple, safe, and affordable. The central part is what we may refer to as a double bubbling tube. The pressures involved are close to ambient atmospheric (1 atm) and the humidification not higher than room temperature dew point (ca . 3 % H2O, or pH2O ~ 0.03 atm).

The "Probble" comes as part of the FCMix gas control system for small fuel cells, but is also sold separately. Contact NorECs for an enquiry.