The portable breath test (PBT) is a handheld breath testing device that many officers carry with them. Like a standardized field sobriety test, it's voluntary and should be avoided. If a portable breath test is taken, the results can be used by the officer to determine whether or not to arrest you. The technology of a portable test isn't as reliable as others, so oftentimes it is not admissible in a trial.
There are two types of breath tests in DUI. One happens before you're even arrested, and the other happens after you're arrested, usually at the station, or in some cases, the jail.
Let's talk about that first breath test. The preliminary or portable breath test is a handheld breath testing device that many officers carry with them. It's about the size of a cell phone. It's often offered as part of a standardized field sobriety testing battery during a DUI investigation. And much like the standardized field sobriety test, it's voluntary, and you shouldn't do it. If you wanna know more about standardized field sobriety tests, click this link.
If you do take a portable breath test, the results can be used by the officer to determine whether or not to arrest you, and even by a judge to determine whether or not that arrest was legal. If you're afraid of a jury knowing what that number is though, don't be. In most cases, those tests aren't admissible in a trial. A jury should never be able to hear what that number is because the technology in the portable breath test isn't as reliable as the one in the evidentiary breath test that's offered after someone is arrested for DUI.