What is the difference between an evidential and a preliminary breath test?

The difference between an evidential and a preliminary breath test centers on their purposes and contexts of use. An evidential test is typically conducted under controlled conditions, often at a police station or another designated area, and is considered reliable enough to be used as evidence in court. This is an important distinction, as the results of these tests can have significant legal implications, such as establishing a defendant's blood alcohol concentration in DUI cases.

On the other hand, a preliminary breath test (often referred to as a PBT) is generally administered at the roadside. It is a screening tool that helps officers determine whether there are probable grounds for further testing. While it provides quick results, its primary function is to assist in decision-making regarding whether to make an arrest or conduct further tests, rather than to serve as definitive legal evidence.

The other options might suggest different aspects, such as equipment and officer training, but they do not capture the fundamental functional and legal distinctions highlighted between evidential tests and preliminary breath tests. This clarity about each type's purpose is vital for understanding their respective roles in law enforcement and judicial proceedings.