On Wed, Jun 22, 2011 at 6:04 PM, Mark Iverson <[email protected]> wrote:
> ** > Joshua: > > STOP THINKING ABOUT VOLUME! Yes, you're right in that the extreme volume > change complicates the measurements, and thats why I and others including > Krivit, are focused on MASS. Think in terms of mass. That eliminates the > complication of the 1700:1 change in volume that you are stuck on. > > If you condense all the gaseous water molecules (i.e., the water vapor) and > you then measure the mass of the CONDENSED LIQUID water (that USED TO BE > VAPOR), that is what the meter is measuring in grams of water (molecules) > per m^3! > You just told me to stop thinking about volume, and then you give me a quantity with units of mass per unit volume. You are thinking about volume, and that's why I am. If that device did as you say, where do you get the m^3 to calculate the total mass of the vapor? But no. That device is not measuring the mass of condensed liquid. It's measuring capacitance, which is affected by the wetness of a dielectric, which corresponds in some known, predetermined way to the amount of water vapor in air. There is no known, predetermined correspondence between the wetness of the dielectric and the mass of condensed liquid that used to be vapor, or the fraction of steam in a steam-mist mixture. No matter how many caps you use. Sorry.
