Accuracy of salt test calibration

I'm a newbie so please forgive me if this is so basic as to belong in the newbie section.

I performed the salt test as directed but only left everything in the bag for 12 hours as opposed to the 24 hours I've seen suggested in some places. My digital hygro registered 65%.

However, twice I've left the hygro outside over night and both time it was dead on with the local weather station's RH reading. What gives? Did I not perform the salt test long enough? Are different results to be expected when leaving the hygro outside?

This whole hygro accuracy/humidification level is necessary but it sure takes a lot of the fun out of this hobby.

HELP (and thank you, too)!

[stewshi]

24 hours is whats suggested and whats been proven to be the amount of time needed, you should try again with this amount of time it should read 75% .... also just because what the weather station suggests at their reading doesnt necessarily mean its that same as where you are.

If your still skeptical you can always just buy a boveda calibration pack for about $5 and use that. Best way and I believe its good for 3 months so you can calibrate a few hygrometers.

I recommend using the boveda testing packs. Sure they are a few bucks, but the accuracy of them are well worth the trouble. Plus, they stay consistent for months, so you can test it later down the road if you would like to.

[longknocker]

I Agree With The Boveda Pack Test. Never Could Get The Salt Test To Work After Multiple Tries.

[Wharf Rat]

Originally Posted by longknocker

I Agree With The Boveda Pack Test. Never Could Get The Salt Test To Work After Multiple Tries.

Well, the Boveda Pak is just a premixed salt test. If you have trouble mixing your own, I'd go ahead and spend the money on a Boveda. If you're a do-it-your-selfer, save the money.

http://www.bovedadirect.com/products...cfm?ITEM_ID=12

[neoflex]

Originally Posted by druturn

I recommend using the boveda testing packs. Sure they are a few bucks, but the accuracy of them are well worth the trouble. Plus, they stay consistent for months, so you can test it later down the road if you would like to.

I have yet to ever get the salt test to work for me.

[bigdix]

If you have any of the HumidiPacks that often come with shipped cigars, throw the hygro in there for 18+ hours at room temp. The packs are +/- 1%, but usually pretty spot on. It will at least get your hygro to within 1%. Worked for me...and it was free...if you don't count the cost of a box or two of cigars.

[dwoodward]

The whole problem with the salt test is that if the consistency of the salt is off just slightly between tests, your hygrometer could have readings as far apart as 10%... I use the Boveda packets. They are easy and you know for sure what the RH is going to be.

[longknocker]

Originally Posted by dwoodward

The whole problem with the salt test is that if the consistency of the salt is off just slightly between tests, your hygrometer could have readings as far apart as 10%... I use the Boveda packets. They are easy and you know for sure what the RH is going to be.

I know this was posted a while ago but is anyone willing to trade for a Boveda pack or link me to where I can buy one? Thanks

[bobarian]

Originally Posted by Wallbright

I know this was posted a while ago but is anyone willing to trade for a Boveda pack or link me to where I can buy one? Thanks

http://heartfeltindustries.com/products.asp?cat=Boveda

[T.G]

Originally Posted by Wallbright

I know this was posted a while ago but is anyone willing to trade for a Boveda pack or link me to where I can buy one? Thanks

Here you go...

http://lmgtfy.com/?q=boveda+pack

[ninjavanish]

Not to discourage you... But I have very very serious doubts about the salt test. Not really the test itself but with hygrometers. Not trying to rain on Anyones parade here but I've never seen anything or any scientific source where the validity of the salt test has ever been proven accurate. And, even if I had seen such proof... It doesn't mean the hygros are reading properly. I've tried on more than one occasion (at least a dozen) to calibrate hygrometers using it with oftentimes terribly inaccurate or even impossibly false results... On several occasions testing up to 10 of the same exact model hygro... On others testing at least 7 different models of hygros... In the same test at once... Getting vastly different readings from each hygro even after calibrating.

The truth is... The only really reliable way (IMO) to tell if your cigars are at the right humidity is to feel your cigars. Feel them between your fingers... Smoke them, literally fondle them until you can pick up your favorite cigar and know by the way it feels if it is going to smoke the way you want it to.

Thanks Bobarian!

Haha and thank you oh wise Adam. The only reason I asked is to see where you guys get it from versus where would be a non reputable retailer or something.

[76GTFan]

Finally decided to do this vs the salt test. Got an additional Xikar hygrometer in route, so time to get it right. I trust my beads but tired of wondering if it is accurate or not. I had ZERO luck with the salt test, at least I still had my doubts.

I keep doing the salt test and find that the outside ambient temp has a affect on the RH. So what is the ideal ambient temp for a salt test to get 75% RH?

[bobarian]

Originally Posted by mscales

I keep doing the salt test and find that the outside ambient temp has a affect on the RH. So what is the ideal ambient temp for a salt test to get 75% RH?

Temps in Celcius but easily converted. http://www.omega.com/temperature/z/pdf/z103.pdf

Clayton, the chemistry of aqueous solutions of various salts has been a laboratory standard for a very long time. The reason for variability is results is in the test method not the chemistry.

[chand]

Do yourself a favor and buy a Boveda calibration pack. The convenience, simplicity, and accuracy are well worth it.

[76GTFan]

Originally Posted by bobarian

Temps in Celcius but easily converted. http://www.omega.com/temperature/z/pdf/z103.pdf

Clayton, the chemistry of aqueous solutions of various salts has been a laboratory standard for a very long time. The reason for variability is results is in the test method not the chemistry.

I believe the scientific validity, but I fear there are too many variables in the common setting. Like others have stated, specific amounts of water to salt would be very helpful. And do different forms of salt make a difference?

[shilala]

Originally Posted by 76GTFan

I believe the scientific validity, but I fear there are too many variables in the common setting. Like others have stated, specific amounts of water to salt would be very helpful. And do different forms of salt make a difference?

On specific amounts of salt to water...
It's real simple. The salt just needs to be saturated. There's a huge margin for error. Even if you have half salt and half water, you're still okay. The solution will still yeild 75% over itself.
That's why we use this test for calibration, it's so simple, and so hard to screw up. What happens is we start thinking too hard, and get scared of the unknown.

Your question about different forms of salt is kind of a loaded one. If you mean "does magnesium chloride yield a different RH than sodium chloride?", the answer is yes.
If your question is "Do different brands of table salt yield a different RH?", the answer is "yes, maybe a fraction of a percentage point."
If your question is "Can I use salt substitute like people use for low salt diets for the test?" the answer is no. It'll yield a different RH, as it isn't table salt, or sodium chloride.

The only thing I can add that may help is that by increasing the surface area of your salt/water mixture, you can move things along a lot faster.
That means that if you use a peanut butter jar lid rather than a soda bottle lid, the air inside your ziplock bag (or whatever) will come to 75%RH a lot quicker.

One last thing...
The depth of the salt/water solution in the peanut butter lid or pop bottle lid or shot glass or whatever doesn't matter at all. A half inch is as good as a mile.