How the breathalyzer results are subject to error

Drunk Driving
By Goodwin Como, P.C.

You spend the afternoon at your buddy’s barbecue. You have a couple of hotdogs, wash them down with a couple of beers, then head home. You feel perfectly fine behind the wheel—you only had two beers over the course of several hours, and you were careful to stay hydrated too.

When you see the police lights flashing behind you, you’re not worried. You know you’re in good shape. The officer makes you walk in a straight line and stand on one foot—which you’re able to do easily. Then he brings out the breathalyzer test, and to your shock, the results indicate you’re over the legal limit.

How do you refute this hard, quantitative evidence?

It may be easy to assume that a breathalyzer will give a more accurate evaluation of your condition than you can, but this conclusion stems from faulty thinking. Breathalyzer tests are also subject to error. One such breathalyzer machine—the Draeger Alcotest 9510—has come under scrutiny recently, and it’s one of the machines that’s used by Pennsylvania law enforcement.

What’s the issue?

Research indicates that there are two fundamental problems with the machine, which affect the accuracy of its testing:

  • Temperature: The results of the breathalyzer test can inflate if a person’s breath temperature is even one degree above the what’s considered the norm. However, no two people are guaranteed to have the same breath temperature, it’s normal for any human’s breath temperature to fluctuate throughout the day.
  • Measurement: One of the two sensors this device uses to gauge blood alcohol concentration is called the fuel cell, which measures the electrical current in the breath. Studies have shown that with repeated use, however, this sensor becomes less and less accurate. Therefore, an individual who is being tested on this device for the first time will have a more accurate result than a person being tested for the 100th time.

If you’re arrested for drunk driving, it’s important to hire an experienced attorney who will pursue all possible avenues of defense. If there’s a case for uncertainty surrounding your breathalyzer results, your attorney may be able to get your charges dropped.