Hygrometers, Humidors, and a bit of model cannon stuff.
I like to think that I have very few vices outside the workshop, where there are quite a few.
But, one of the vices in which I indulge occasionally, is a good Cuban. And I make a point of indulging no more than 3 per week.
And, actually, that does add to the number of vices in my workshop, because that is where most of the Cubans (and Bolivians, and other central Americans) meet their destiny.
SWMBO does not encourage cigar smoking in the house for some reason, but I quite like the stale cigar smell in the workshop. Come to think of it, maybe that’s what is keeping the tigers outside.
To cut to the story, my son in law, James, gave me the Humidor pictured above, for Christmas. A great gift, which I greatly appreciated. Mind you, I have a sneaking suspicion that he might have had an ulterior motive, because James too enjoys an odd cigar, and he likes his cigars to be at the perfect humidity of 75% when he visits the workshop, “for a chat” or whatever.
The humidor box is very nicely made, with a Spanish Cedar internal lining. Made in Indonesia. It shuts perfectly tightly and just the size for about 50 coronas. And it has a hygrometer to measure the humidity.
But…… it comes with instructions to calibrate the hygrometer. WTF! If I buy a Mitutoyo gauge, I assume that the calibration is correct. What is this “calibration”. And then there were the instructions for calibration….
- place a tablespoon of salt in a plastic dish, and add JUST ENOUGH water to make it damp.
- Place the dish, and the hygrometer in a zip lock sealed bag and let them stand for 6 hours.
- After that time the hygrometer should read 75%
Well that all sounded Mickey Mouse to me, so I asked my fellow model engineers at our second last meeting.
As usual, in our group of 15-20 participants, one person clearly knew ALL ABOUT humidity measurements, because he had worked in the munitions experimentation industry.
Next meeting, he brought the following hygrometers……
But! Do you know which method the explosives experts used?
The salt dissolved in water method!
Apparently that method is accurate to less than +/- 0.5 %.
So that is what I did. And after the hours of waiting, when the humidor hygrometer should have read 75% it actually read 65%.
There was a screwdriver slot at the back, which enabled me to adjust the calibration on the hygrometer.
Apparently the explosives scientists carried a kit which contained a selection of the above salts, and they used them to calculate the humidity of the air before conducting their experiments.
NOT MANY MODEL CANNON POSTS LATELY!
But I have been working on finishing Armstrong RML number 2.
Not much to show but I have been working on the gears, brake, and chassis……
Love the post John,
Enjoyed the odd Davidoff years ago but they became rather pricey.
I suspect I prefer the smell to the smoking these days but even that’s a rarity.
Enjoy as the cliche has it.
And it just so happens that the good old common salt (Sodium Chloride) gives near enough to bang on the humidity you seek.
Amazing combined knowledge in our little group. Another good reason to be a member.
You have a local model engineering group. I am envious.
Where are you located John?