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Breathalyzer results shouldn’t be an automatic DUI conviction.

On Behalf of | May 19, 2018 | DWI |

You’re driving home after spending a pleasant night at a friend’s house. You’re not speeding, and although you had a couple beers over the course of the evening, you don’t feel impaired. Suddenly, you see those tell-tale lights flashing in your rearview mirror. You pull over.

The officer asks you whether you’ve been drinking that night. The next thing you know, they’re taking you through the gamut of field sobriety tests, all of which you pass. But then the officer takes out the breathalyzer machine, and your reading comes back above the legal limit. You’re shocked. Is it possible you were driving while drunk and didn’t even realize it?

While the breathalyzer test may seem like the most concrete, scientific proof of intoxication, it is still subject to error. The accuracy of the Draeger Alcotest 9510—the breathalyzer equipment used by law enforcement agencies in New York and many other states across the U.S.— has been the subject of scrutiny recently. Researchers found multiple issues with the equipment that could inflate its readings:

Breath temperature

It’s normal for a person’s breath temperature to oscillate over the course of the day. If your breath is one degree centigrade over normal breath temperature when you take a breathalyzer test, it could boost your reading by six percent—enough to make you appear legally drunk.

Fuel cell

The Alcotest 9510 detects blood alcohol content using two sensors: an infrared beam that measures the amount of light that goes through your breath and a fuel cell that tests the electrical current in your breath. Researchers found that the more this piece of equipment is used, the more the fuel cell degrades, and the less accurate its results.

It’s important to understand that if your breathalyzer test yields high results, it’s not necessarily the end of the line for you. If an experienced DUI attorney can inject sufficient uncertainly about the validity of your results, they could ultimately get your charges dropped.


Law Offices of Joseph J. Tock