I am running an experiment in which I have packaged a moisture sensor in a small ceramic package (1cc) connected to a glass capillary with a leak rate somewhere around 1E-3 atm cc/s. I bake out the package then evacuate the air inside to achieve 0% RH inside, then place the package (without backfilling, so there is a vacuum inside) in a chamber at 37degC and 90% RH. If I understand correctly, Fickian diffusion would have the steady-state RH inside the package equalise with the outside environment (90% RH), but I've found it to reach steady state at 30% RH. Is anybody able to explain this phenomena? Does a leak this small (the pore size in the capillary is around a micron in diameter) act as a porous membrane, and therefore the moisture content gradient will be discontinuous?
- Badges
- Science topic
- Similar topics
- Engineering
- Petroleum Engineering
- Gas