How do the tests work?
Breathalyzer tests work by measuring the amount of alcohol present in a person’s lungs. The alcohol content of the lungs reflects the amount of alcohol that is in a person’s bloodstream, something that scientists proved after a lot of experimentation. In fact, they have been able to show that the ration of breath alcohol to blood alcohol is a fairly precise 2,100 to 1.
So does this mean that you swallowed a sip of alcohol and immediately took a breath test that you could be found to be drunk? Unlikely, given the way the tests work. Though your breath could smell like alcohol, the air in your lungs would not have had a chance to absorb the alcohol and that is what the test measures.
Are breath tests accurate?
Though scientists have worked hard to ensure that breath tests accurately portray a driver’s level of impairment, the reality is that nothing is perfect. One study out of the Wisconsin State Laboratory of Hygiene found that only 33 percent of Breathalyzer tests administered in a test corresponded to the blood test results. Another study out of the University of Washington estimated that Breathalyzer accuracy can vary by as much as 15 percent from actual BAC levels.
The reality is that a range of factors including your diet, operator error, calibration problems, even mouthwash can throw off the results of a breath test. These possibilities for trouble underscore how important it is to hire a skilled Minnesota DWI attorney who understands the process of challenging unjust results.
Source: “How Breathalyzers Work,” by Craig Freudenrich, published at HowStuffWorks.com.