psychrometer chart

[Fred Sturm]

Thanks for the tips. Ron's is a graphic chart with curved, intersecting
lines. Unfortunately, to read below 20% you need the dry-bulb temp to be
well above 70 degrees F. Don's two are quite different from one another.
The chart at http://www.bigelow.org/virtual/handson/humidity.html does
show a full range of humidities for a full range of temps (Farenheit).
The web-site at http://www.bom.gov.au/lam/humiditycalc.shtml has a
"calculator" which gives an output of rel hum when you input dry and wet
bulb temps (Centigrade). I was interested to find that the chart in the
former had 19% for dry 70F/wet50F, while the calculator in the latter
had 11% for 21C dry/wet  10C (Which, if I calculated right are the
equivalent F and C). Neither mentioned barometric pressure (though I
assume each used a constant).
Regards,
Fred Sturm
University of New Mexico

Ron Nossaman wrote:
> 
> At 08:34 AM 03/01/2002 -0700, you wrote:
> >Can anyone point me to a reasonably complete chart of temps/humidity
> >levels for a sling psychrometer? The chart I got with mine (ten years or
> >so ago) lacked numbers below something like 25%. I really just need for
> >dry bulb in the range of 65 to 75 degrees.
> >Thanks,
> >Fred Sturm
> >University of New Mexico
> 
> Fred, try this.
> 
> http://www-das.uwyo.edu/~geerts/cwx/notes/chap06/Psydew.JPG
> 
> Ron N