RE:RE:already inventedEven if there is a desk top device that indicates "measurable THC" try proving how recent or even if could be second hand smoke. Blech. Useless. Without a device that indicates parts per million in an liter of blood as the various alchohol devices do, it's worth approximatley zero. The complete lack of information from the company indicates this device is about as useful as a road side sniff test by an officer. It might manage a legal search of the vehicle or a road side sobriety test, but as I mentioned, a smell of mary jane gains the same advantages.