Hydration, The Salt test

[suburude63]

Hi guys! This was intended for Cigar smokers but its a very valid test for hydrate's accuracy. suburude

 

 

The Salt Calibration Test

 

Over the past few months, I’ve provided you with tips on how to properly cut and light your cigars, I’ve discussed good cigar etiquette, and we even lent our advice on spotting counterfeits and golf. Now it’s time to learn how to harness that ever-elusive hygrometer.

 

Even the most amateur Stogie Guy knows that cigars need humidity for proper storage. Since they are hydroscopic in nature, stogies will – over time – dry out in an arid climate or absorb moisture in a humid one. Dry cigars yield high combustion temperatures, leaving the smoke hot and acrid on the palate. And wet cigars tend to fend off lighting, burn improperly, and split their wrappers.

 

What we need then, Goldilocks, is a happy medium between too dry and too damp. For the most enjoyable smoke, this equates to 12 to 14 percent of the cigar’s total weight in moisture (or about 60 to 70 percent relative humidity). If you have a humidor – which you should – your hygrometer measures relative humidity. That should make creating a cigar-friendly environment easy to monitor, right? Wrong.

 

Hygrometers, whether mechanical or electronic, can be grossly imprecise and may require adjustment or replacement. The simplest way to verify the accuracy of your hygrometer is to perform a simple salt calibration test.

 

Let me begin by mentioning that my BA in political science does not exactly qualify me to discuss the intricacies of chemistry. In fact, I have no clue why the salt calibration test works…it just does. You’ll have to take my word on that.

 

So here’s what you’ll need to perform this simple experiment:

(1) Distilled water (purchased from any grocery store)

(2) Coffee stirrer (or other thin, clean object with which to stir)

(3) Bottle cap (Snapple bottle caps work perfectly)

(4) Empty wide-mouth jar with lid (like an old mayonnaise jar)

(5) Tablespoon of plain table salt (I suggest Mortons – it’s made in Chicago)

(6) Your hygrometer (duh)

 

Place the tablespoon of salt within the bottle cap and slowly add distilled water to the salt while stirring with the coffee stirrer. Only add just enough water to moisten the salt so that it becomes a thick paste. Do not add enough water to dissolve the salt!

 

Place the bottle cap with salt gently into your wide-mouth jar and add your hygrometer. Make certain the sensor is exposed and is not blocked by the sides of the jar. Seal the jar so there are no leaks and put it in a place out of direct sunlight and with a stable, cool temperature (like your closet).

 

Leave the setup undisturbed for a minimum of eight hours. After that, check the reading on the hygrometer through the glass jar – it should read on or near 75 percent relative humidity.

 

Due to the salt paste reacting with the confined air, the ambient relative humidity within the jar will be exactly 75 percent. Most inexpensive hygrometers are only accurate to within 3 percent, so do not be surprised if yours reads 72 or 78 percent. Whatever it reads plus or minus our 75 percent benchmark is the amount of error of your hygrometer.

 

If your hygrometer has an adjustment potentiometer then, by all means, try to tweak it to exactly 75 percent relative humidity. You should repeat the salt calibration test after making any adjustments. If your hygrometer can’t be adjusted but the reading is close, then my advice is to not worry about it; just remember that your hygrometer is X percent off – either high or low. If the reading is grossly in error and you are unable to adjust it, you need to replace it.

 

Once you confirm your hygrometer’s accuracy and maintain a relative humidity of about 65 percent in your humidor, your cigars will age properly and be in peak condition when you’re ready to partake in their delicious flavors. Happy smoking!

 

-Patrick A

[zeebee]

Or,...................you could simply buy a digital.

[ballcorner]

Thanks for the post - believe it or not I got out of bed this morning frustrated by the fact that I have four hygrometers on my desk - each with its own idea of what my humidity level is in this room and I was right in the process of wondering which one is accurate when I read your post.

 

I have to go find some jars . . . thanks.

[RogueBrit]

A couple of small points. It is just as valid to test digital hygrometers as well as analogue types - they are all subject to calibration during manufacture, and being 'digital' does not imply infallibility, and their initial and ongoing accuracy relies on electronic components performing within specs.

Second point - the salt test is very useful, and the only practical test available to those outside a laboratory. It only confirms accuracy, however, at that one level of relative humidity. It is perfectly possible for hygrometers to be bang on at that level, but inaccurate at other levels - bearing in mind the level being checked is not the one we are generally measuring, which is in the range of, say, 30% to 60% RH. Similarly, electronic components performance can vary with temperature, and you are only confirming accuracy at the temperature at which the test is being carried out. For these reasons, it is always best to invest in a good quality hygrometer - these are less likely to suffer such defects.

 

In fact, by using alternative chemicals, hygrometers can be checked at other levels - magnesium chloride, for instance, allows checking at various levels, dependant on temperature. For those interested see this interesting article - http://ezinearticles.com/?Prevent-Mold!-Hygrometer-Calibration--Tips-from-a-Bellingham-WA-Home-Inspector&id=602308. You need to cut and paste the whole link in your browser - I notice that only the first part has appeared as a highlighted link.

 

 

Finally, some people assert that as we do not need to measure humidity to a fine level of accuracy, say only plus or minus 10%, all this effort is not worthwhile. This is not a safe conclusion however - errors multiply, and you want to eliminate as many as possible. Again, I hear people say that they have never worried about this, and their guitars have not suffered. Or that vintage instruments often come to light that have simply been thrown in an attic, or similar, and suffered no harm. In these cases - if the guitars are truly unaffected - it is in spite of the treatment they have received, not because of it. Many do suffer - and the effects of, for instance, long term extremes, can be irreversible and expensive to correct - if they can be corrected at all.

 

My experience comes from trying to control and measure humidity in confined spaces in the laboratory - I can tell you that it is not as easy as might appear! Others can do as they wish but, for myself, I am not happy to rely on chance when it comes to my own expensive and treasured guitars. just my thoughts.

 

Roger

(edit - spelling)

[RogueBrit]

Shoot - the above link doesn't work. Do a google on Hygrometer Calibration and you will find it a little down the page. It's one of the most useful and authoritative links this search will turn up.

 

Roger

[zeebee]

From the following site: http://www.cigarextras.com/index.asp?PageAction=Custom&ID=6

 

How to properly calibrate a hygrometer

 

Follow instruction for the device if specific instructions were provided. Otherwise, most hygrometers can be easily removed from the humidor and will need to be removed to calibrate the hygrometer. Some hygrometers are not designed for removal like some "pre-calibrated" models. Most hygrometers can be removed by gently pressing from the back. Your hygrometer has been sleeping in a closed box for a while and you will wake it up now by placing the hygrometer in a wet cloth for 1/2 an hour or until the unit reads 95 - 100%, then return its normal place and allow 2 hours to reset. If the hygrometer does not reach 95-100% as described above, you will need to calibrate the hygrometer as detailed below for the salt test .

 

Salt Test

This test is for analog hygrometers which are not pre calibrated. The salt test is not recommended for digital/electronic models and performing the salt test on these models will void the warranty.

 

Like chemistry? neither do I... so I will keep this chemistry stuff as brief as possible . In nature, when salt and water (NaCl and H2O for you science aficionados), are in a saturated solution at equilibrium, the resultant humidity is 75%. This gives a fantastic reference point to calibrate your hygrometer. Here's the procedure you can use to create this science experiment: you need a Ziploc bag, a beer bottle cap (or other small container) a small amount of salt (regular table salt will work, save the Mediterranean sea salt for cooking), and regular tap water.

 

Place the salt in the bottle cap (or other small container). dampen the salt with the water. Do not put so much in that the salt gets "soupy". You want a damp pile of salt in the bottle cap. Place both the hygrometer and the bottle cap full of damp salt in the Ziploc bag and seal it well. (It is important not to let air in or out while the test is going on.)

Keep it like this for at lest 8 hours. After 8 hours in the damp salt environment, the actual humidity inside the bag will be 75%. Compare it to your hygrometer; your hygrometer should also read 75% if it is properly calibrated. 99.9% of hygrometers will not read 75 at this point, if yours does, today is your lucky day and we encourage you to buy some lottery tickets (please remember me if you win!) If your hygrometer does not read 75, then you will know exactly how far off your hygrometer is off at this point, note the amount and direction, such as subtract four or add 10. Now if you are tired of reading, you can apply the above adjustment to your hygrometer reading. You can also calibrate your hygrometer to read accurately using the instructions below.

 

Please read this section carefully as this information will contradict most printed information found elsewhere as well as falsehoods and misconceptions about calibrating a hygrometer. The world is full of self proclaimed experts who will tell you how to calibrate a hygrometer incorrectly. If you choose to follow their advice, remember that we sell replacement hygrometers in all shapes and sizes and we can help you replace the hygrometer you break when you don't follow our instructions.

 

To calibrate your analog hygrometer after performing the salt test turn it over to the back. Look in the center, if you see a screw of some sort, examine it more carefully. If it is painted red or if it appears to barely have a slot to accept a screwdriver it is not the type that can be set with a set screw. If it does have a slot or a true calibration screw proceed to "Instructions B", otherwise follow directions listed at "Instructions A"

 

Instructions A To calibrate this style hygrometer you will need to remove the rear stainless steel plate. Using a very thin flat blade of a screwdriver circle the edge of the plate till you locate an appropriate location to loosen the plate and pry it from the hygrometer. Beneath the plate you will see one of the configurations below. Some models have a plastic insert, remove this and set aside remembering how it was placed so you may replace later. Inside you will see a coil which should not be touched. You will see either a ring about the size of a nickel or an adjustment tab, turning either of these will adjust the reading of the hygrometer, but don't do that just yet. Now holding your hand over the back of the hygrometer, turn it over and notate the reading and either add or subtract the difference noted from the salt test. This will be the reading you will want your hygrometer to display, this reading will not be 75 as your hygrometer is not in the salt test environment at this time. Turn the hygrometer over again and turn either the adjustment tab or the adjustment ring and at the same time watch the needle at the front till it comes to the setting you have determined above. Your hygrometer is now properly calibrated. Begin to reassemble the parts, replace the plastic insert if there was one and replace the stainless steel back and apply pressure to the back while holding the bezel only, do not apply pressure to the glass lens as the lens will crack if pressure is applied.

 

Instructions B For only the hygrometers with an adjustment screw at the rear center (read information above on how to differentiate types before proceeding) get a very thin flat screwdriver ready to make adjustments. Before adjusting anything you must do some math. Look at the front of the hygrometer to determine the humidity reading now add or subtract the amount you calculated after you did the salt test. This result will be what you should set your hygrometer to. Using your screwdriver rotate the set screw until the hygrometer rests at the humidity reading you determined above. If turning the set screw does nothing and does not change the reading you are using the incorrect instructions and you must follow the instructions listed under instructions A.

 

At this point if you completed the steps listed above you are done for now, but you should salt test your hygrometer every 6 months or so to be sure of the accuracy.

 

If all this science and tests reminds you too much of high school and you want nothing to do with it we have two suggestions!

 

Use a Boveda Hygrometer Calibration Bag a easy one step system to calibrate any analog hygrometer. This can be used inseted of the salt test, but you still must follow the calibrating instructions.

 

Purchase a digital hygrometer as they are accurate and require no calibration.

 

 

 

 

 

 

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[RogueBrit]

The corrosive affects of a salt laden atmosphere can affect metal parts of any type of hygrometer, of course, and the point made in the above article, particularly re warranty, is a good one. You don't want to overdue it - I have tested quite a few over the years with no long term bad effects - and will continue to do it - however testers beware, and everyone takes their own responsibity on this!