Evaporation measurment
Evaporation measurment
(OP)
Hi Every one, First of all appologies if this is the wrong forum. But I have a large water basin 150 m x 50 M by 4 m deep made of concrete. This basin has to be tested for leaks and is filled with water. I am testing to BS 8009 which states that the max drop in waterlevel should be the lesseer of 10mm or depth/500 + evaporation, my problem is how to measure the evaporaion? any ideas?






RE: Evaporation measurment
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RE: Evaporation measurment
If you're already doing field measurements, you might as well measure the evaporation as well. Get yourself a standard Evaporation Pan. They're basically big flat pans that you set outside. They're straightforward, in that you put water in, measure the depth, wait, and then measure the depth again. You obviously have to account for rain and things that may happen during the test. Set it up and run the evaporation test at the same time as your other test and you'll have a more accurate number for evaporation in the very specific conditions of your test than you'll get trying to calculate an estimate from multiple variables.
Note that the evaporation rate from a large body is less than from an evaporation pan. The body of the pan heats up and contributes to evaporation. There's a reasonable amount of literature about scaling factors to go from pans to lakes, though, and you should be able to come up with a good value. My notes say that 0.7 is commonly used for many applications, but you might be able to come up with a better value for your specific case. The term you'd want to look up is 'Pan Coefficient'
RE: Evaporation measurment
RE: Evaporation measurment
RE: Evaporation measurment
RE: Evaporation measurment
Mike McCann
MMC Engineering
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RE: Evaporation measurment