San Diego DUI Breath Testing involves measuring the amount of alcohol in a sample of exhaled air of a person arrested for DUI. The use of breath tests to determine the amount of alcohol in a person’s blood stream is an indirect and therefore inaccurate method of obtaining a person’s true BrAC.
San Diego DUI Breath Testing is not an accurate method of determining blood alcohol level.
How San Diego DUI Breath Testing is argued to work
After you consume alcohol, be it wine, beer or otherwise, it gets absorbed into your bloodstream from your mouth, throat, stomach and primarily from your intestines. As the blood travels through your body it travels to your brain which is why you can feel the effects. It also travels through you liver where it immediately begins the process of removing it from you blood stream.
In addition, the blood travels through your lungs, where some of the alcohol molecules move across the membranes of the lung into the air using the same process that allows you to breath in the oxygen you need to live. At this point your lungs contain alcohol molecules along with molecules of oxygen etc. and the concentration of alcohol molecules in your lungs is related to the concentration of the alcohol in your blood.
Intoxilyzers operate on a principle known as “Lambert-Beer Law,” which states, basically, that the amount of infrared light absorbed by your breath sample is proportional to the amount of alcohol in the sample. In other words, the more alcohol there is in your breath sample, the less infrared light that gets through the chamber to the detector. However, there are other compounds, called “interferents,” which can also block the infrared and the Intoxilyzer can not tell them apart.
So not only can these machines be fooled they are also based on faulty science theory.
San Diego DUI Breath Testing & Henry’s Law
The underlying scientific principle of the Intoxilyzer is known as Henry’s Law. Henry’s law states, essentially, that the concentration of a volatile chemical in vapor form is proportional to the concentration of that same chemical in liquid form. This is absolutely true in the laboratory, but in humans, the proportions are not constant. This means that the Intoxilyzer can easily overstate the amount of alcohol in your blood.
San Diego DUI Breath Testing is not accurate and can not be relied on as being accurate.
San Diego DUI Attorney Bradley Corbett is available anytime to answer your questions regarding San Diego DUI Breath Testing.