[Dueller]

First, if ya gotta ask "Have I had too much to drive?", you probably have.

While I'm not familiar with personal BT's, I have a PBT (portable hand held) model used by law enforcement. It is very simple and highly inaccurate...most often reading much higher or lower than the Intoxilizer 8000, the "real" thing used at PD's for testing. For example, PBT's usually don't distinguish between mouth alcohol vs. deep lung breath alcohol concentration. This is one of the reasons PBT's are not admissable in most jurisdictions to show level of intoxication but are usually admissable to show probable casue to take the real test.

Final note...the current federally mandated level of .08 BAC is unbelieveably low. Most people don't think they're impaired until they reach the .13-.15 level.