There is some serious negativity in these comments that I don't understand. I for one think that there is a strong need for a weed breathalyzer, and I encourage

There is some serious negativity in these comments that I don't understand. I for one think that there is a strong need for a weed breathalyzer, and I encourage you in your efforts. This is a fundamental and necessary part of the legalization of weed. Some people here are worried about the efficacy of such a device and the motives of partied involved - and rightly so. But consider for a moment: the cops don't need to use any sort of test or device in order to arrest you if they suspect you of smoking today. They throw you in a jail cell and let the lab do your blood work in a couple months. And that process is very imprecise! You could have used cannabis weeks ago, then driven totally sober, but it would still show up in your blood tests.