Re: Help with atmospheric water vapor partial pressure experiment.

D Akers writes:

Is my thinking correct? If I could stop the air from crossing the filter
membrane, would the dP across the filter paper likely stabilize and be
equal to the difference between the saturation vapor pressure and the
prevailing partial pressure of water vapor in the air? In other words;
would evaporation from the filter paper cease?

Having trouble following your description, nor do I follow on what physical
principle you are isolating or differentiating vapor pressure of a certain
gas (water) or its analog.

It sounds like you are not measuring a differential between saturated vs
ambient vapor pressures at the ambient temp, but merely a change in the
captured vapor pressure due to the temperature drop in the system from
evaporation. Which is to say, a rather clumsy and uncalibrated wet-
bulb/dry-bulb psychrometer, something you were trying to avoid.
.