[Stoves] humidity sensor resources

[Charlie Sellers]

Frank, good to see you at ETHOS (here is a quick video I took of the Sunday outdoor stove demo session http://youtu.be/KuJLf2ALMG4) and I agree that we have a need for something like this for fuel drying applications (such as when trying to prepare batches of feedstocks with a consistent moisture content - e.g. for use at regional stove testing labs.  Here is what I have experience with, or found available:

	* I couldn't track down much at all about those oven sensors - either some sensor characteristics, or sources of them that might provide some description of what they are or how they work - so I worry that we won't be able to find enough info on their associated circuitry to use them easily (but the big ferrite magnets found in each oven are well worth harvesting).

	* When I was doing medical device development we used Sensirion's super quality SHT line of tiny CMOS sensors (they throw in a DTS temperature sensor for free), but while they are now a tenth of what we paid for them... they are still ~$25 at places like Sparkfun.  For the same price, or much less, you can get consumer-grade weather station "instruments" complete with remote LCD readouts.  

	* This bare sensor example caught my eye because its is so absurdly cheap ($3-$6) and often readily available - http://www.amazon.com/Virtuabotix-DHT11-Digital-Temperature-Humidity/dp/B0066YD3GM.  You need some circuitry to use it or any other one, but hackers have published exactly how to do it using a variety of microprocessor platforms - for computer-aided data logging:  http://embedded-lab.com/blog/?p=4333

If anyone can suggest alternative methods (and applications for them in our arena) then I'd like to hear about them.  Or about experiences with inexpensive drying in bulk of things like wood chips, for TLUDs or similar. 

Charlie
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