Posted by Curbie on December 7, 2009, 9:50 pm
I'm trying to calculate the evaporation rate of an algae raceway pond
using the formula (which seems applicable) given here:
Does anyone know how to calculate the values for Pdw and Pw???
PDP = saturation pressure at room air dewpoint, in.Hg.
PW = saturation vapor pressure taken at the surface water temperature,
Posted by Jim Wilkins on December 7, 2009, 11:27 pm
Posted by Curbie on December 8, 2009, 2:45 am
On Mon, 7 Dec 2009 15:27:19 -0800 (PST), Jim Wilkins
I put that table into a spread-sheet with a column to covert mb to
inHg so I think I can start testing that evaporation equation.
Posted by Jim Wilkins on December 8, 2009, 12:46 pm
A surface film of oil will retard evaporation considerably.
You can measure the evaporation rate with a pizza pan of water on a
weighing scale. A piece of yarn hung over it will show air flow. I
think the rate vs velocity curve straightens out around walking speed,
it's similar to wind chill.
Radio Shack sells temperature and humidity displays with remote
sensors, the older model I have is quite good on temperature and
within about 10% on humidity, The sensors can be checked and compared
in a steamy shower room at 100% humidity.
Posted by Curbie on December 8, 2009, 2:55 pm
On Tue, 8 Dec 2009 04:46:40 -0800 (PST), Jim Wilkins
An interesting idea, I be a bit concerned that the oil may impede the
algae's ability to get at atmospheric CO2, but easily tested and worth
Another easy test, I'd like to get the math to work, but good
verification and backup if I can't.
Does Radio Shack's device have data logging capabilities?