You may have encountered this before: a cop orders you to pull over on the roadside and asks you to step out of the car. Asks you a few questions and pulls out a machine you are supposed to blow into.
How Breathalyzers work
Breathalyzers are equipment that compute a Partition Ratio, an estimation that measures one part of alcohol in your breath and equates it to 2100 parts per million in your blood. This is the 2100 to 1 ratio. The partition ratio is an estimate based on an idealized average; in reality the actual ratio is an estimate based on an idealized average; in reality the actual partition ratio can vary affected by diet, metabolism, and medical conditions.
Many breathalyzers do not measure alcohol directly. They measure Methyl group compounds with over 2000. The human breath may show as much as 200. This can come from inhaling pumping gas, paint fumes or handling glue or similar compounds, as these chemicals may also be absorbed through the skin. Breathalyzers can measure anything that has small amounts of alcohol in it like mouthwash, toothache medicines, acetone present in the breath of diabetics, and people on high protein diet.
Does it get errors?
Yes. Most states require some form of duplicate analysis or getting two readings within .01% of each other to be accurate. The range of error can be as much as .04 on a .01 test that equates to an error rate of 40%. These false positives and the range of errors can be problematic, especially when a driver may have been drinking earlier and no longer register an elevated BAC. This is why hiring a good DUI attorney is important.
Can you refuse the Breathalyzer?
You can refuse the Breathalyzer and the field sobriety tests. In Kentucky, however, you are subjected to implied consent statute. By virtue of the Commonwealth that issued you an operator’s license and permitted you to drive your vehicle of choice on Kentucky’s roads, you have implied consented to a test of your blood, breath, or urine. But this can be discussed by your lawyer.
Know your rights; be wiser when facing a breathalyzer test.