Comment Re:But does it work? (Score 5, Interesting) 707
This seems to make sense to me. The breathalizer is supposed to measure the blood alcohol content, and this is done by measuring the alcohol content in air expelled by the *lungs* (with a knowlege of partial pressures).
But if you equally weight beginning readings with ending readings, then you can be skewed by the first reading, which comes from the air in the mouth, instead of the lungs (giving low scores for people with time since their last drink, and people high scores with a recent last drink).
I would think that this method would give a more accurate reading by filtering out the readings from 'mouth air' and giving preference to 'lung air'.
But regardles, tests should have been done using both methods, and comparing to blood test to see which returns more consistantly accurate results. I wonder if those tests need to be made public as well.