Mechanics of the Breathalyzer
If you are ever pulled over by a police officer who thinks you might be driving drunk, you will most likely be required to submit to a series of field sobriety tests and one or more tests to measure your Blood Alcohol Concentration, or BAC. If these tests reveal that your BAC is over the legal limit of .08, they may be very strong evidence against you in court.
Alcohol on the Breath
The most commonly used type of BAC test is the breath test, administered using a device called the breathalyzer. While the reliability, admissibility, and accuracy of the breathalyzer has been challenged by several court cases and DWI defendants, use of the breathalyzer is still very common, and breathalyzer evidence is still very damaging during a DWI trial.
When you take alcohol into your system, it is absorbed into your bloodstream and carried throughout your body by the blood vessels. This alcohol-laden blood eventually passes over the alveoli (tiny air sacs) in your lungs, where the exchange of oxygen and carbon dioxide takes place. During this exchange, trace amounts of the alcohol in the blood leak out into the air which is then expelled from the lungs.
Breathalyzers function by measuring the tiny amount of alcohol carried on the breath, and using a mathematical formula to calculate the proportional amount of alcohol in the blood.
Although breathalyzer evidence can seriously damage your DWI defense, an experienced Austin DWI lawyer knows how to challenge the reliability of breathalyzer results in court.