A PBT or portable breath test is a type of field sobriety test used to investigate DUI. A PBT is much more susceptible to false positives, residual mouth alcohol, and less reliable than a State Administerd Breath Test. The NHTSA (National Highway Traffic Safety Administration) recommends that a PBT be used only after the officer has had the driver in his view for a minimum of 15 minutes and then only to confirm the findings of other field sobriety tests. In fact, the results