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How Breathalyzers Work

For as much as your breath test results can affect your GA DUI case, it is important to understand how breathalyzers work. Statesboro DUI lawyer Matt Hube has undergone thorough training on the various aspects of DUI defense, including defenses that attack the breathalyzer machine itself.

The police use two different types of breathalyzer machines in order to measure your blood alcohol content (BAC): the fuel-cell breathalyzer and the infrared light breathalyzer (because the infrared version is the more common in Georgia DUI cases, that is the version that will be covered below). Before discussing how the machines do this, it is important to understand what exactly is being measured in order to calculate your result.

What Breathalyzers Measure

The Georgia DUI breathalyzers are designed to measure the alcohol content from the air in the deepest part of your lungs, known as the alveolar air. Because this area of your lungs has a high concentration of blood vessels, it is believed that the alcohol content in this air will most closely match the alcohol content in your bloodstream. This is due to the unique properties of the alcohol molecules which enable them to pass through cell walls—and travel through your system—faster and more easily than other molecules.

How Breathalyzers Work Internally

When you exhale into the breathalyzer, air from your lungs travels past a lamp that emits several different wavelengths of infrared light. It then passes through a filter wheel, which is designed to trap everything but the alcohol molecules. The light passing through this filter wheel is measured by a photocell and turned into an electrical pulse. A computer microprocessor then calculates your BAC level based on the electrical pulse it received.

One of the main problems with this machine is that the chemical compounds in alcohol are similar to a number of other chemicals. Although the government insists the filter wheel knows the difference between ethyl alcohol and other substances, studies have shown that this is simply not true. Sometimes, the breathalyzer will measure an innocent chemical in your breath as alcohol, and state that you are drunk when you are not.

Ultimately, breathalyzers are computers, and computers are only as good as the code they are programmed with. When you blow into a breathalyzer machine and it begins to calculate your result, it is not taking your individual bodily make-up into account. It will assume that you have a 2100:1 ratio of breath alcohol to blood alcohol; it will not adjust its program depending on your gender, body temperature, age, or lung capacity. It uses the same cookie-cutter algorithm for everyone who takes the test.

If your interests were more than mere curiosity, call Statesboro DUI lawyer Matt Hube today. His unique knowledge of Georgia DUI defense and GA DUI law will help defend your rights against a criminal charge or license suspension. Call today!