re principle of the breathalyzer william burchill williamb ee ubc ca wrote does anybody out there know how the hand held breathalyzer used by our police works i would like to hear about this and the more general problem of detecting smells by machine thanks william williamb ee ubc ca from what i have read about these little gadgets it works on a electrochemical galvanic principle the sensing unit has a chemical matrix which produces an electrical voltage proportional to the amount of chemical compound it is designed for in this case i believe it is the hydroxyl group i have also heard not tested since common gasoline is also a member of this hydroxyl group it will also cause a failing breathalizer failure next time you get stopped for dui say you just siphoned gas from your neighbors car you know the oklahoma credit card and chances are you won t get a dui ticket jerry long long spk hp com disclaimer opinions are my own and do not reflect those of my employer
