First of all I want to point out that I am not a chemist, I am an electronics engineer. I have no idea if what I want to do is even possible to do DIY fashion and without to much fancy equipment and that is why I turn to you guys who are the expert on these things.
As a hobby project I am building a breath-acetone meter. Then sensor I use is an electro chemical tin dioxide (SnO2) semiconductor sensor from Figaro sensors called TGS822. It is sensitive both to alcohol and acetone and I have it working so that I can take readings from it. However to be able to link the sensor readings to what gas concentration it corresponds to I need to get a know fix point. In the sensor manufacturer used ethanol vapor at 300ppm as calibration level so that would be optimal but not necessary, any known concentration between 100-1000 ppm should work.
I guess that you have to start with a know concentration of alcohol say 40% (vodka?) and then dilute that further with water until the alcohol concentration is lower. Then take a small enough amount of that and dissolved in a known amount of air and place the sensor in that mix. However I have now gotten lost so many times in my calculations with molecular mass and unit conversion between ug/l and ppms etc that I have almost given up, but before I give up I thought that I would ask you guys for help first.
Is what I want to do possible without to much special equipment?
If it is possible can someone tell me what proportions to use?
Any word of advice is highly appreciated.
If anyone is interested to read more about what I have done so far please take a look at http://jenslabs.com/category/electronics/ketosis-detector/
Thank you in advance.