Although these devices are technically "water resistant", they are sometimes described as "water proof" (even in STM materials), and the data sheet permeability of the gel is quite low. Clearly these devices can survive immersion for at least several hours, but for how long, really...
There are several posts on here asking questions about this, but no quantitative answers. Has anyone (ST engineers especially) conducted experiments on device drift or lifetime for continuous immersion in water (without worrying about aggressive chemicals or surfactants)?
What is the drift or lifetime for direct immersion?
What about if a flexible membrane is used as an outer layer of protection (e.g. a thin layer of nitrile rubber). Polymer membranes won't be impereable, of course, but would be something which would not resist pressure change but should limit the sensor to contact with water vapour rather than liquid.
