Phone breath testing apps: are they any good?

You may have seen them on people’s phones. You may have even thought about buying one yourself. But you wonder, do they really work? Could they tell you with enough accuracy whether you are too close to Tennessee’s legal limit of 0.08 Blood Alcohol Content? Are they good enough to prevent you from being stopped for a DUI?

One television station decided to try out three breathalyzer apps to see how they performed in the real world. They went to a local bar and had five people begin drinking. They then tested the individuals during the next two hours to see what types of measurement the apps would produce.

And just to keep everyone honest, they also invited a local county sheriff office to send over and officer with a law enforcement breathalyzer to check the results of the phone apps. A state trooper was also present to observe the drinking and discuss the effect of drinking on driving ability.

The good news is they found two of the apps were reasonably accurate. Their measurements were close to the sheriff’s deputy’s official breathalyzer results.

The problem was the third app was consistently off, in one case producing a reading of 0.54 when the deputies reading were 0.84, which if you were stopped in Tennessee, would lead to your arrest on a DUI.

As the sheriff’s deputy noted, if you are pulled over, it is their numbers that will matter. Could these apps be useful to alert you when you should take a cab? They could be, as long as you could trust the calibration is not way off, as it was with one of the apps.

Even with official law enforcement breath testing, accurate calibration and proper use is important, and the question with a phone app may come down to how lucky you feel when trusting its measurements., “2 Test: Are Breathalyzer Apps Accurate,” KARE staff, January 8, 2015

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