humidity sensor

[system]

Thanks for your replies.

Put this in a sealed container and it will stabilize at 75% RH

I appears that other salts can aslo be used:

http://www.conservationphysics.org/satslt/satsalt.php

I'm not yet brave enough to put my lone $17 sensor in a bag of salt solution.

What allowance have you made for voltage feed variation

I have covered this problem see:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1259616399