I am trying to use the BME280 in a project that will be outdoors. The challenge is therefore allowing water vapour in (to allow the sensor to detect humidity) whilst protecting the electronics from water damage.
It seems one solution is to use a Gore Vent. For example, see the Ruuvitag which uses the BME280 and includes a "Gore IP67 certified vent membrane".
Thinking about it, I was wondering how this works. Doesn't a Gore membrane only allow water vapour to pass one way? That being the case, wouldn't water vapour either get in but not get out or not get in at all?
Any recommendations as to Gore Vents welcome.