Sling Psychrometer

T

Trouthead

Newbie in the jungle
New to the forum but old to cigars. I have always been interested in relative humidity in the weather and realative humidity in my cigars. So.... years ago in an EBAY searching mode I typed sling psychrometer (wet/dry bulb hygrometer) into search and ended up buying one. I live 1/2 mile from the local NOAA station and generally my home readings are plus or minus 1 point from the NOAA stations.

Today I searched EBAY for more sling psychrometers and found a bunch from $10.00 to $100.00. All considered pretty much laboratory accurate, and certainly they have the potential for years of checking of humidor psychrometers. Set you hygrometer out side, check your sling psychrometer and adjust. :tu

Just surprised no one else has posted on this. Now all that being said am I missing anything???
 
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I think you're proposing using a sling psychrometer to calibrate the humidor's hygrometer or realize its error? The only problems with that are that for a successful sling psychrometer you need two perfectly calibrated thermometers - just adds another level of uncertainty and calibration. If your sling psychrometer readings are within 1% of what the NOAA says and you trust that, why not just use the NOAA readings if you want to calibrate your hygrometer using the outside ambient air?

A more accurate (IMHO) approach to calibrating a hygrometer is using the salt test method. Information about that can be found with a simple search in this forum.

Welcome to CS! Go ahead and introduce yourself in the New Gorilla Forum so we know who you are :tu
 
Have done the salt test, but this is just playing around. Frankly 63% or 69%, or 67%, I am not sure it matters too much to the cigar. I figure 3-4 points around 65% is just fine. But since there appears to be so much concern over hygrometer accuracy, I thought I would throw something else into the mix.

You mention the salt test which I have been doing for years. I often get readings that vary. Wet the salt, seal the bag, and 12 hours later I get 74%, and at 24 hours I get 72, and at 36 hours I might get 75. Is it the salt, ( I think not) or are most of the electronic hygrometers pieces of junk.

Maybe it is all a moot point if beads will maintain humidity without worry. It is still fun to play with a little bit, and that is what the psychrometer is for, play. :tu

And thanks for the spelling correction, My wife the English teacher(really) would approve.
 
I was just talking to Trouthead about this.
I think a guy can go one step better if so desired.
That's by using Saturated Sodium Nitrate @66% rather than saturated Sodium Chloride @75.5%.
The little hygrometers we use tend to waver across the scale we're interested in, which is generally a range of (liberally) 60-75degrees F. and 60% to 70% RH.
66% salt falls as close to our range as salts get, and Sodium Nitrate is very inexpensive and readily available (it's a meat preservative).
It makes sense to stay as close to 65% as possible when calibrating a hygrometer, if you keep your cigars close to 65%. If you keep your cigars at 75%, then by all means you should be using table salt (without iodine, because Potassium Iodide added to table salt bumps it up a little over 76% rather than the 75.7% of plain non-iodized salt.)
I even offered for Trouthead to try some cause he digs this stuff, and now I can't find my stash. (Although I found about 50 pounds of other salts. Ugh.)

Last but not least...
I just say this stuff cause I'm excruciatingly anal about these things.
Personally, I don't care what my hygros say unless they say something way off.
If my cigars are smoking fine, I'm all set. I don't care if the hygro says 63% or 68%. :tu
 
Just jump right in Shilala. :D

I go in cycles with coffee. Right now I am not drinking any, but that could change. At the start of the summer I got drinking non alcholic Kalua with a shot of cream in some Kenyan. Pretty much a girly man drink, but I enjoyed it for a while. considering the nearest Starbuck is 150 miles away, it is hard to get a hardcore big city coffee habit going here.

A different salt.....

I did get a D in physics in HS, come to think of it I also got a D in chemistry, but I do remember there are lots of other salts other than NaCl. Now are we talking Chemistry or physics here? How come the big comercial packet makers have not done other salt test kits?
 
I don't think I could maintain my coffee habit on Starbucks coffee. I like my watered down half-caff Maxwell House with milk. :)

I don't know why no one makes tests kits for other salts, except that they're expensive.
Boveda uses salts in their packets for controlling humidity and they're expensive. The only test kit they have is the 75.5%, I do believe.
My guess is that they're just following tradition.
We're used to calibrating our hygros at 75%. Table Salt is everywhere.
It's simple and it makes sense.
Like I mentioned earlier, I'm just incredibly anal. I've always needed to have very accurate instruments in my work, so the Sodium Nitrate makes sense to me.
I can then take the precision working knowledge and dumb it down to "what's good enough". If I'm using table salt and a good calibratible hygrometer, that's easily good enough.
If I'm using table salt and a Wally Hygrometer, I may as well just guess at my humidor's RH. It's just as accurate. :tu

Trouthead said:
Just jump right in Shilala. :D

I go in cycles with coffee. Right now I am not drinking any, but that could change. At the start of the summer I got drinking non alcholic Kalua with a shot of cream in some Kenyan. Pretty much a girly man drink, but I enjoyed it for a while. considering the nearest Starbuck is 150 miles away, it is hard to get a hardcore big city coffee habit going here.

A different salt.....

I did get a D in physics in HS, come to think of it I also got a D in chemistry, but I do remember there are lots of other salts other than NaCl. Now are we talking Chemistry or physics here? How come the big comercial packet makers have not done other salt test kits?
Click to expand...
 
Trouthead said:
Just jump right in Shilala. :D

I go in cycles with coffee. Right now I am not drinking any, but that could change. At the start of the summer I got drinking non alcholic Kalua with a shot of cream in some Kenyan. Pretty much a girly man drink, but I enjoyed it for a while. considering the nearest Starbuck is 150 miles away, it is hard to get a hardcore big city coffee habit going here.

A different salt.....

I did get a D in physics in HS, come to think of it I also got a D in chemistry, but I do remember there are lots of other salts other than NaCl. Now are we talking Chemistry or physics here? How come the big comercial packet makers have not done other salt test kits?
Click to expand...

Different salts will give different relative humidity when they are saturated, vis a vis this link e.g. You might try posting this in the coffee forum.

Those guys can be a little OCD with their measurements and fuddling and fussing around.
I bet you might even get a good discussion going on the best time to first crack/ second crack vs RH and ambient temperature in there.

shilala said:
YES!!! :D
Today I'm loving some Pumpkin Spice/Kona hybrid I mixed up. :r
Oh, wait, you were talking to Trouthead. Please excuse the breach of etiquette. :r
Click to expand...

Yup those guys are OCD, but not me, I'm not OCD. :D

ps Welcome to CS
 
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