Funny, I've had a hygrometer for many years that works on a similar principle.
I'm guessing (guessing
, I say...
), that the difference is in the amount of work
that can be performed by the mechanism involved...for the hygrometer, it just has to be enough to register a difference to perform the measurement (usually over a "long" period of time)...
Still, I agree, the basic physically principles are likely similar, if not the same.