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How accurate are breath alcohol tests?

On Behalf of | Dec 30, 2019 | DUI |

If you have been stopped by law enforcement in Minnesota on suspicion of drunk driving, you know that you cannot refuse to submit to a breath alcohol test without facing potential additional penalties. The results of these tests are often used as the primary evidence in DUI cases; but how accurate are they?

Breath alcohol tests are used by law enforcement to determine the amount of alcohol in the blood of drivers suspected of driving under the influence. These devices work by measuring how much alcohol is in a breath sample provided by blowing into the device. According to, there are several factors that may affect the accuracy of breath alcohol test readings.

Some tests require software that must be kept updated. Should the software be out of date, it may cause glitches in the machine’s operation that may affect the readings. Additionally, many breath alcohol testing devices require regular calibration. The devices needing to have the batteries replaced or to be charged may also affect the results of BAC breath tests.

Perhaps you finished your last drink within 15 minutes of getting stopped and submitting to a breath test? You may have trace amounts of alcohol still in your mouth that may affect the results of your breath test. Consequently, it may seem that you are over the legal BAC limit for driving when actually, you are not. Likewise, using products such as breath fresheners or mouthwash that contain alcohol before giving a breath sample may also lead to falsely high readings.

This post is meant for general uses only; the information included should not be taken as legal guidance.

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