The Intoxilyzer 9000
The Intoxilyzer 9000 is an evidential breath testing machine that has been approved in the state of Georgia since January 1, 2013. Since 2016, it has been the only approved machine in the state.
The evidential breath test is evidence that holds a lot of weight with judges and juries. The prosecution does not need to prove that a person is less safe, only that they were above the legal limit within (3) hours of driving. Understanding the principles of breath testing, and the Intoxilyzer 9000, will assist in fighting this number.
What are the principles of breath testing? Without going into too much detail, the lungs contain small air sacs called alveoli. The alveoli are surrounded by capillaries. This is where blood, by diffusion, is able to release carbon dioxide and absorb oxygen.
For alcohol to diffuse from blood to breath, it must become a vapor or gas from liquid. Henry’s Law basically states that, in a closed system, the concentration of a material in the gas state above a liquid, will be proportional to its concentration in the liquid state. When given enough time in the lungs, the concentration of blood in the breath will reach a defined balance with the concentration of alcohol in the blood. This is called equilibrium.
At equilibrium the concentration in the breath is proportional, but not equal to the blood alcohol concentration. At perfect equilibrium, (at 34 degrees Celsius), the amount of alcohol in the blood is approximately 2100 times higher than the amount of alcohol in the same volume of breath.
How does the Intoxilyzer 9000 measure the breath alcohol content? The person blows air into a heated hose with a disposable mouthpiece attached. The air then enters the sample chamber, where infrared light is pulsed through the chamber at a defined frequency. Ethyl Alcohol (the alcohol that is in alcoholic beverages), absorbs different wavelengths of the infrared light in a unique way that can be identified from other substances. It then measures the quantity of ethyl alcohol by measuring the amount of absorption that occurs.
This is the basics of how breath testing works, and what the Intoxilyzer 9000 does to measure a person’s breath alcohol content.
About the author: Joshua Ott operates Caselock Inc., specializing in expert testimony and reviews for cases involving alcohol and/or drug impairment. Joshua has extensive knowledge and training obtained from ten years as a police officer in Metro Atlanta. He has extensive experience training law training law enforcement officers as well as courtroom preparation and testimony. He resides in Woodstock, Georgia with his wife, daughter and Miniature Schnauzer, Gus. For more information, visit caselockinc.com.