Tiny blood alcohol concentration (BAC) testers have become popular attachments to modern day smartphones. These devices claim to function like mini Breathalyzer machines, which can evaluate a driver's state of alcoholic intoxication to determine if it's safe and legal for him or her to drive. However, are these devices accurate and could the use of one help prevent drivers from drinking and driving or getting into trouble with the law?

The short answer is, "no." According to an article on Fortune, using different smartphone-based BAC testers did not reveal that the devices yielded similar results and it was difficult to know which of the devices offer the most accuracy.

Furthermore, even though the author felt too drunk to drive after two drinks, the smartphone devices yielded BAC results of .036 percent and .057 percent. According to the results, the devices were saying that the author was sober enough to operate his vehicle legally, but he claimed that he didn't feel that way. He said that his speech was slurred and his coordination was marred, like he could trip.

Perhaps some of the smartphone Breathalyzer devices are more accurate than others. The problem is, it's difficult to know which one is going to yield a correct result. In this respect, the best piece of advice to drivers wishing to avoid a DUI charge is to simply not get behind the wheel of an automobile after drinking any quantity of alcohol. If by some chance, however, you do get pulled over and charged with a DUI, you will be entitled to defend yourself against the charges in court.

Source: Fortune, "Can you trust a smartphone breathalyzer?," Jason Cipriani, accessed Sep. 14, 2017