Metrology is the science of measurements. The terminology of "uncertainty of measurement" captures the basic idea that measurements come with a built in uncertainty.
The concept applies to the use of alcohol testing. Don't let anyone tell you that the machine is 100% accurate. If you blow into that machine, and it reads a .080, it does not actually mean you were necessarily a .080. In fact, as I look over the BCA charts, which the BCA will disclose in a DWI case, the uncertainty chart shows a 99% confidence interval that your actual alcohol concentration was between a .0705 and a .0895. If you blew a .085, the chart shows a 99% confidence interval that your actual concentration was between a .0750 and a .0950.
Let's take it up a notch. Blowing a .16 or higher leads to increased penalties. If you blew a .160, the 99% confidence interval says that your actual concentration was between a .1416 and a .1784.
I hope you can see the significance here for people sitting right near the border of the statutory limit. This is an argument for reasonable doubt. Hey jury, there's a decent chance this guy's alcohol concentration was below the limit!
But if you walked in thinking, "what can a lawyer even do for me? I blew a .08, it's a sealed deal," you'd be wrong.
If you or a loved one are charged with a DWI, give me a call at (651) 337-9876.