You spent the night out at a local bar while enjoying a football game, and you decided that you’d be fine to drive home. After all, you had plenty to eat and didn’t drink more than a few drinks all night.

You left the bar feeling good, but when the red and blue lights started flashing behind you, you knew that there was the potential for trouble. Smelling alcohol, the officer asked you to take a Breathalyzer test, and it came back over the .08% limit.

You don’t think it was accurate, at least not based on what you drank that night. The officer only took one test, too. What should you do?

Know that BAC tests aren’t always accurate

To start with, these tests aren’t always accurate. Your blood alcohol concentration (BAC) changes over time and may be picked up more easily by the Breathalyzer if you burp or regurgitate during the test. If it hasn’t been at least 20 minutes since your last drink, the test may not be accurate at all.

Given correctly, a breath test is accurate. However, there is a risk of human error. Usually, officers are asked to take two breath samples, too. Why? It shows if the machine is calibrated correctly. If the two samples, taken only a few seconds apart, are too far off from one another, then you know that the machine isn’t accurate.

Breath test results help officers establish probable cause, but it’s not necessarily enough for a DUI charge to lead to a conviction. If you’re arrested, remember this when you seek legal advice.