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How Accurate Are Breathalyzer Tests?

Posted by William Kirk, Partner | May 19, 2014 | 0 Comments

If you are stopped for a suspected DUI, the chances are that an officer will ask you to submit to a Breathalyzer test. Unlike a blood test, a Breathalyzer test allows the officer to get an immediate determination of your blood alcohol level. However, unlike a blood test, Breathalyzer tests are more likely to be inaccurate.

As you may know, a breath test only measures how much alcohol is in the air that you exhale to give an estimate of your blood alcohol level. This is contrasted with a blood alcohol test that directly measures how much alcohol is in your blood. As a result, the breath test is by nature going to be less accurate than a blood test.

Some factors that can affect the reading of a breath test outside of how much you drank can include your body temperature, respiration rate, and even whether you have something in your mouth like gum or breath mints. In fact, something as simple as burping can wildly throw off the results of a breath test.

To help ensure the accuracy of a breath test, the officer administering the test must follow certain protocols including making sure that the subject does not burp, throw up, or regurgitate for 20 minutes prior to the test. In addition, the officer must properly calibrate and service the device. Failure to take any of these steps may result in the inadmissibility of the breath test results.

Contact a King County DUI Attorney

You should know that a failed breath test does not automatically mean that you will be convicted of a DUI. There are many reasons why a breath test may give a false positive. As a result, you should consult with an experienced DUI attorney to discuss your case and learn options for your defense. Contact the DUI defense law firm of Cowan Kirk Gaston Wolff at 1-866-822-1230 to learn how we can help you.

About the Author

William Kirk, Partner

Bill Kirk has been named a Super Lawyer by Washington Law and Politics Magazine every year since 2003. He currently serves on the Board of Regents to the National College for DUI Defense and is the President of the Washington Foundation for Criminal Justice. Bill is one of only two attorneys in this state to pass the National College's Board Certification Exam.


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