Quantitative range of 0 - 145 mg/dL (0.0% - 0.145% BAC). The QED Alcohol Saliva Screen is a technologically advanced Alcohol Screen device that can be used as an accurate, quantitative measurement device for obtaining blood alcohol levels using a saliva sample. Qed Saliva Screen works through a preset chemical reactive process that requires no user intervention, a color bar rises to the level of alcohol present in the system in much the same way as a mercury thermometer. QED oral alcohol screens are a rapid method on-site test procedure. The Q.E.D. Oral Saliva Screen measures the amount of alcohol in bodily fluids, commonly called blood-alcohol concentration, or BAC. Q.E.D. alcohol saliva screen is very sensitive to the presence of alcohol.