Factors that can impact breath test accuracy

On Behalf of Sanchez Burke, LLC

Seeing those blue lights come on in your rearview mirror can be a horrible feeling, and you may wind up feeling even worse if the law enforcement official who pulls you over asks you to submit to a breath test. Breath tests, when conducted correctly and under the right conditions, are often precise, but there are several outside factors that can make their results less-than-accurate.

Part of the problem associated with breath test devices is that they typically take an indirect estimate of your blood alcohol content, rather than an official reading. In fact, Alcohol Alert reports that the reading a breath test device produces can vary by as much as 15 percent from your actual blood alcohol content. The penalties associated with drinking and driving in Louisiana are substantial, so if you have any doubt whatsoever that the results of your breath test are accurate, it may serve you well to get to the bottom of things. So, what types of outside factors can affect the accuracy of these devices?

Poor calibration

A breath test device must undergo periodic calibration in order to function correctly. If this does not occur, or if administrators do not do so properly, it can lead to a falsely high breath test reading. Inaccurate calibration is a common reason judges dismiss driving under the influence charges during a trial.


The temperature, too, has the capacity to impact breath test readings. While breath test devices are sensitive to the temperature in the air, the internal temperature of the test subject can also affect the accuracy of test results.

Electronic factors

Electronic interference near the area where you take your breath test can also impact test results. Electronic factors might include signals from cellphone or radio towers and police radios, among other possible sources.

If you receive a conviction for DUI, you will likely face considerable fines, substance abuse treatment obligations and even time behind bars, among other possible penalties. If you feel your breath test results were inaccurate, consider taking a second look at them.

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