Humidity

[tc3driver]

One out of three aint bad! Calibrate the other two and you are golden!

Thanks for demonstrating the fact that hygrometers really, really need to be calibrated! Imagine how bad the analog ones are!

The problem being that the two that are off, are not calibrate-able, or at least not that I can figure out. The big square one on the bottom came with a high dollar Humidor that is "calibrated in the factory and does not ever need calibration"... same story for the cheap xicar.

And/or it just tells you that using a baggie to check hydrometers may not work all that well (and it often doesn't, unless there is a fan in the bag).

Interesting... I know I have a tiny fan laying around here somewhere... I can hook one up to a battery and toss it in there see if that makes a difference.

edit:


We'll let that sit for a couple days and see how that turns out.

Ok - if you can't get your humidor to precisely 70% with temperature at precisely 72 degrees, your cigars will fall apart.

To get the most accurate humidity reading possible, you need a chilled mirror hygrometer...

The heart of a chilled mirror hygrometer is the sample chamber, through which the gas to be measured flows. The chamber contains a coolable mirror and an optical system that measures the mirror reflectivity. During operation, the mirror is cooled until dew or frost begins to condense on it, changing the reflectivity and the optical output. The optical signal drives electronics that control the temperature of the mirror to maintain a constant layer of condensation. The mirror is therefore held at the dew/frost temperature. The dew/frost temperature is a fundamental property of water vapor and therefore an inherently reliable measure of moisture concentration. A temperature sensor imbedded in the mirror provides a direct measure of dew/frost temperature.

Why they are inherently reliable:

Chilled mirror hygrometers are inherently reliable because of this operating principle, and because the dew/frost temperature is measured directly – there is no need to convert parameters such as resistance, voltage, etc., to humidity through a calibration equation. We ensure temperature reading accuracy by using ultra-stable mirror temperature sensors that are calibrated against a NIST-traceable reference standard.

During operation, no long-term error can exist. If an error in mirror temperature somehow appeared, its dew or frost layer would immediately begin to increase or decrease, and the control circuit would heat or cool the mirror to restore the proper frost layer. Therefore, as long as the control system is operating, the mirror temperature must remain exactly at the dew/frost point.

Even more interesting... how can one fit one of these in a humidor...

BTW welcome Twotacotuesday :)