Humidity-meter

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Revision as of 16:46, 12 September 2009 by Jan Goofy (talk | contribs)
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The Humidity-meter

The hole setup - green box is 5V supply
Close-up, with 10 Eurocent for scale. Pin distance is 1.27mm I belive (0.05MIL)

Why meassure humidity? Simple, it affects very much how you presive ambient temperature. So 20.0°C can seam verry hot, or very cold, depending on humidity. If, and I must stress this out, IF you have a fetish for meassuring things, next after temperature, humidity would be the logical choice.


Thats why I got a couple of thise babies: HIH4000-002 Solid-state humidity sensors. Thise are maintemance-free and with a hobby-level accuracy.


The setup:

Give her 5Vdc, a 47K resistor and you are up and running, it does not get more simple than that. Currently meassuring: 2.27V, this translate into: 45.8%Rh, this is a normal humidity, atleast around here. will drop during winter due to the fact that the air outside will be cold and when heated up, the RELATIVE humidity will drop.

For more on Relative Humidity, please see: Wikipedia page on %Rh


This was just a QaD setup (yet it took me long enough to overcome CBA), on a long term, it will be logged somehow, I have a pretty good idea who will help me with that :-) - more to come.