promille meter
eirp thx for your volunteer, but i hope there will be 1k pcs of sensor per month to calibrate, so I am not sure if your liver and especially lungs could mange callibrations. Assuming two points callibration, and next veryfication of parameters it would be a lot of breath. It would be really hard work to do. ;-)
Yes there is special formula for calculation of BAC to mg/dm3. I have found it yesterday -
[BAC] div by 1500 to 2600 = [mg/dm3]
where coefficient depends of the person
PaulHolland good point, except of the speed and temperature of gas. From the bag it would be uncomparable with human breath. And of course humidity of such air will be different than breath one. It is not a problem with IR sensor, but we have made SnO2 sensor, which are very sensitive on humidity. (In this application it is not problem because human breath has always near constant temperature and humidity)
Finally it could be very usefull!!
I've found the article, the author said that change of temperature of part of degree - for instance fast, deep breath of 20s could change (decrease !!!) result of police alcohol breath meter response of 12% !!!
Maybe someone could test it empirically?? Every information very appreciated
regards
KamW