resistive humidity sensor wisdom

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pibeans

Joined Jan 11, 2013
3
I have canniballised an old Oregon remote unit to re-use the humidity sensor - which I assume from appearances is resistive.

(I have DHT11 and DHT22 sensors to hand but distrust them)

The project will ultimately - probably - be a wireless module with ATTINY and an RPI "base-station".

The accepted wisdom for resistive RH sensors is to excite them with AC to avoid polarising the sensor. But the overhead of an AC input and rectification to a simple measurement is a pain.

So: is it acceptable to activate and sample the sensor for a short period intermittently (a few s every few m)? Possibly/probably reversing the polarity of the supply from one sample to the next?

TIA / piBeans
 
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