If you are arrested in Illinois for Driving Under the Influence (DUI) and are not dead, unconscious or seriously injured, the officer will ask you to perform what are known as Standardized Field Sobriety Tests (SFST). Following these tests, the officer will ask you to take a Preliminary Breath Test (PBT).
The results of the PBT are not “official” and cannot be used against you to prove your intoxication. However, those results, along with the SFST, will provide the police with the grounds to arrest you for DUI. Following the arrest, the officer will ask you to take a different type of breath test, the results of which can have specific criminal and driver’s license consequences.
The PBT is administered at the arrest scene by use of a hand held device that gives an estimate of your blood alcohol level, or BAL. 625 ILCS 5/11-501.5 Normally the official breath test is given at the police station with a desktop device, although there are a few on-sight devices that are official, as they are properly certified as being accurate. However, those can only be administered by a qualified technician and only after you have been placed under arrest for DUI, whereas the PBT is given prior to your arrest.
Another difference between the PBT and the official test is that, as is the case with the SFST, there is no penalty to the driver for refusing to take the SFST or the PBT. On the other hand, if you take the PBT but refuse the official test, you will be written down as a refusal.