Digital Hyrdometers

[KayakinBoy]

Besides the "clear button", is there any way to calibrate a digital hyrometer?

 

[Rob_k]

i don't think so. the one i use at work doesn;t have instructions as to calibration. i believe when it powers up it self calibrates. makes me wonder though...

 

[puffnstuff]

on analog hygrometers, calibration/correction can be done by adjusting the dial.
on a digital hygrometer, the closest thing to calibration is probably just making a note of the inaccuracy (after salt-testing it), and accounting for it when taking readings.

 

[KayakinBoy]

Alright, so I've been salt testing the digital, and my analog, for over 10 hours in a sealed Humidor Jar. The plastic ones. all that is in the is the hydrometers, the cap with salt, and a piece of cedar they are sitting on. The digital seemed really off when I first got it, and now they are BOTH reading 69%. is this a good enviroment for this test?

I had no gladware, because college kids mircowave things....

 

[mrjinglesusa]

I'm trying to figure out what a "hyrdometer" and "hyrometer" are. :laugh:

For what it's worth, my digital hygrometer (Caliber III) says that it was factory calibrated and no further testing is needed.

 

[Rob_k]

i think you gotta take the cedar out , may be absorbing some of the moisture in the chamber and giving you a low reading. all that i have read is the cap/salt and hygrometer only, nothing about cedar. take care...Rob

 

[Pyre]

I've read a lot of people are using the "humi-pak" for testing their hygrometers. If you don't know, humi-paks are little zip lock bags sold at cigar shops that are supposed to keep the contents at exactly 70% RH. I prefer using these for testing. I've had mixed results using the salt method.

 

[KayakinBoy]

Cute jingles! :laugh: I had to type in a hurry today, work and car estimate from being plowed into by the little old lady.

the humi-pak is a pretty good idea! I might try that! As for testing, the analog and digital are now dead on, without changing them, so I would have to think that they are both off by 5 points. I will get it figured out sooner or later.

 

[Sunward]

I have 2 analogue,and one Digital Hygrometer. The analogue can be adjusted using the screw in the back. For the digital, it reads 5 % below RH using the salt test. It took very long to stabilize as well ~24 hrs. I just subtract 5 points RH and this is annoying cuz it costs 5 times more than the analogue. I might try using a 50/50 solution of propylene glycol/ distilled water and see if i get 70 %, maybe get some use out of my chemistry degree. If this works, i will repost.

Luuuuuuuuuucccyyyyyyyy.... can you splain why my smokes are soggy??

???

 

[KayakinBoy]

mine is off by 5 too, when i opened it up this morning, it read 75, so i'm happy! lol

 

[Sunward]

okay, i said i would post, if i found out any more info on calibration, so here it is, (from a news forum, i cut out the blahs) :
Any solution with a fixed composition has a fixed vapor pressure at a
given temperature and total pressure. If the solution has only one
volatile component (water), then the vapor pressure is caused by that
component only (i.e., you won't find PG in the vapor phase).

" By coincidence, the vapor pressure of a saturated solution of PG is about
70%.To put it more simply, PG is a hydroscopic substance - It absorbs moisture from the enviroment (like a salt shaker does in humid weather). The distilled water evaporates until the ambient humidity approaches 70%. At that point the PG won't allow any more moisture in the air. This is called
"Vapor pressure". Conversly, if there is too much moisture in the air, the
PG solution absorbs the excess, bringing the system _down_ to 70% as well.

blah blah.. then it reads: Does the Propylene Glycol help make it so it will only humidify to 70%??? Answer:
71% specifically. PG is fairly hydroscopic. it will only allow water to evaporate till the ambient stabilizes at that level. It will also actually absorb moisture from a too-humid enviroment to stabilize at 71% as well. This makes it ideal for regulating a humidor. "

So, I tried this mixture, 50/50, and it reads dead on 71% in a ziploc bag.... hope this helps, cuz i lost one hour of good cigar smoking time looking how to do this when i could have just read the previous posts and used a humipack!

 

[KayakinBoy]

lol, thanks. :laugh: