Humidity "salt test"

SamGuss

Active Member
Joined
Jul 9, 2002
Messages
1,907
I ran across a post earlier today that made mention of doing a "salt test" to check out if the humidity was right or the humidometer was reading correctly or something along these lines.

Can someone here fill me in?

Thanks,

Sam
 

DaveWF

Official CP Entertainment
Joined
Jan 16, 2001
Messages
2,897
In a nutshell (I'm sure someone will supply a link to a very indepth description):
Mix 1 tablespoon of salt with just enough DW to make a paste.
Put this in a small container like a bottlecap
Put the bottlecap and your hygrometer in a ziplock style baggie with enogh free stadning air that neither touch the other
Now doublebag the whole thing
wait EIGHT hours
doun't cheat at 4, really wait 8
The exact humidity in the bag is now 75%
adjust your hygrometer accordingly
double check if necessary (yeah, wait 8 hours again)
you'll now have a calibrated hygrometer

hope this helps,
Dave ;)
 

FatherTiresius

Watcher of the Skies
Joined
May 4, 2002
Messages
1,364
There's a faq somewhere that explains it in detail, but I don't have the link handy. Basically the idea is that a saturated salt solution has a vapor pressure such that it will create a constant 75% humidity in a sealed container. So you can use this to calibrate your hygrometer. You put the hygrometer in a baggie with a soda cap (or other small cup-like substance) full of salt and a little water. You want just enough water to wet the salt, but not dissolve all of it. Seal the baggie and wait a few hours. When you check it again, your hygrometer should read 75%. If it doesn't, use a small screwdriver to turn the little calibration screw until it does. At that point you should be all betterbetter calibration-wise.
 

SamGuss

Active Member
Joined
Jul 9, 2002
Messages
1,907
Awesome - thanks guys. I am 90% my hydrometer works just fine, but at the same time I have also been having more cigars on hand in the humi also - so rather be safe than sorry.

Sam
 
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