If you have been pulled over on suspicion of drunk driving in Nebraska, you may have been asked to submit to a breath test. Law enforcement officers use these devices to measure your blood alcohol content level without taking an actual blood test. Using this reading, officers can determine whether you are driving over the legal limit.

However, studies show that readings from breath tests are not always accurate. In fact, they may lead to a wrongful DUI charge. According to the State University of New York at Potsdam, one in four people tested with a breath test will have inflated readings.

How do breath test devices work?

Rather than measure the amount of alcohol that is in your blood directly, roadside breath test devices use an exhaled breath sample. The machine picks up ethanol alcohol in the breath sample and then converts that amount to a BAC level. Breath test devices detect other methyl group structures that are similar to alcohol, which can make results unreliable.

What factors influence results?

Methyl group structures can be found in a number of substances other than alcohol, including human saliva. Furthermore, other factors are known to alter breath test readings. These include the following:

  • Dirt, pollution and smoke in the air
  • Relative humidity and temperature of the air
  • Residual blood, vomit or food in the mouth
  • Gasoline, cleaner or paint fumes
  • Electrical interference from officer radios and cellphones

Breath test devices must be calibrated to yield accurate readings in various temperatures. The officer using the machine must also know how to do so properly, as some false readings are the result of improper use of the machine.

If you have taken a breath test, there are a number of factors to consider to ensure your reading was accurate and reliable.