Shares 1. Air pressure is the weight (or force) of the atmosphere at any particular point. Although you canât feel it or see it, air pressure plays an important part in weather, and can be demonstrated with some really fun experiments.
familiar with breathalyzers that require drivers to provide a deep-lung sample by blowing into a tube or other sensor. In contrast, the breath-based system being developed by Autoliv Development is designed to unobtrusively analyze alcohol in the driverâs breath. Drivers will simply be able to enter the vehicle and
Preliminary Breath Test. The officer may also ask the driver to take a Preliminary Breath Test (PBT) as part of the field sobriety tests in Virginia The PBT is a roadside breath test used to determine the presence of alcohol in the driverâs system. If the PBT detects any alcohol, the police officer has probable cause for a DUI arrest (Va. Code Â§18.2-267(D)). Like the other field sobriety tests in Virginia, this test is not required and the results will not come into evidence against the driver unless he challenges probable cause for his arrest.