How to Calibrate a Hygrometer?

I have a Nappolion II Humidor, it came with a fancy looking analog hygrometer. I tried calibrating it with the steps I read here.
After 24 hours, the hygrometer read 45%. It has a flat head screw on the back, and when I turned it to adjust the level to 75% the whole thing spin in its casing, I eventually got it to 75%.

Also, I am currently seasoning the humidor. I filled up the humidifier, and placed 3 small bowls of distilled water, one in each drawer. I did this about 32 hours ago, and I placed the hygrometer in the humidor at the 24 hour mark.

The hygrometer currently reads 85%. Is this normal while seasoning? or is my hygrometer just malfunctioning. I plan to buy a digital hygrometer soon before I dare to put any cigars in.

[icehog3]

Originally Posted by v00d3W

I plan to buy a digital hygrometer soon before I dare to put any cigars in.

A good move, Richard, as analog hygrometers are notoriously inaccurate. It migh be hard to say what your current RH actually is, could just be the hygrometer.

[688sonarmen]

Question. Maybe I'm missing something but it takes at least 24 hrs to get the hygrometer up to 75% Rh in a very small sealed environment. So can't we expect the hygrometer to take just as long to read the Rh in your humidor? The reason I am asking is my humidor is 69% Rh with more than enough (65%) beads in it. I just calibrated my hygrometer 2 days ago and was wondering if the hygrometer needs a few days to drop to the range of the humidor.

[N2Advnture]

Originally Posted by 688sonarmen

Question. Maybe I'm missing something but it takes at least 24 hrs to get the hygrometer up to 75% Rh in a very small sealed environment. So can't we expect the hygrometer to take just as long to read the Rh in your humidor? The reason I am asking is my humidor is 69% Rh with more than enough (65%) beads in it. I just calibrated my hygrometer 2 days ago and was wondering if the hygrometer needs a few days to drop to the range of the humidor.

Howdy.

Digital hygrometers can be off even after calibration. I've seen "drifts" from +/-1% to +/-10%.

The RH Beads also have a +/- 2% range, so this may explain the 69% reading (+2 on both accounts).

Additionally, weak batteries can account for inaccuracy in hygrometers as well as the quality of the hygrometer. One NIST cert. hygros are dead on but they run in the hundreds of $.

Opening and closing your humidor as well as adding and removing cigars can affect readings as well.

I hope this helps

Mark

Originally Posted by icehog3

A good move, Richard, as analog hygrometers are notoriously inaccurate. It migh be hard to say what your current RH actually is, could just be the hygrometer.

well it's been a couple weeks, and my Humidor is sittin on 70%, 70 degrees, right where I wanted it!

I wanted to thank all that helped out while getting my box where it needed to be!