The State Is Improperly Certifying Its Breath Alcohol Machines

Posted On August 22, 2023 Charles Ramsay

What happens when you certify your breath alcohol machines with controls that are mislabeled? You turn innocent citizens into criminals.

Unfortunately, the state crime lab has been certifying its breath alcohol machines improperly for a long time. And this isn’t me saying so. 

The scientific literature has been saying this for over 40 years! Kurt Dubowski, one of the most published researchers in alcohol testing, wrote in 1979:

“Commonly-encountered directions for use of the 34C simulator in breath-alcohol analysis, e.g., those in the Breathalyzer Model 900A Instruction Manual, call for an alcohol solution concentration of 1.21 mg alcohol/mL (= 1.21 g/liter) to produce an effluent-alcohol concentration of 0.100 g/210 liters… The instrument readouts thus over-report the actual vapor and breath-alcohol concentrations and their assumed blood-alcohol equivalents by the same 1.3%  Such overestimation is forensically indefensible...” - Kurt Dubowski

The problem that Dr. Dubowski was referring to is the air/water partition ratio used to test the breath alcohol machines. In the old days, labs simply used an air/water partition ratio provided by the breath machine’s manufacturer.

It seems the MN state lab is using numbers from the holdover of the days of the Breathalyzer 900A - an ancient machine!


During the annual certification procedure, the state crime lab introduces its breath machines to reference gas produced from a solution of water and alcohol. They do this to test the machine’s accuracy. 

The problem is, the state is using an outdated air/water partition ratio. 

They should know better.

More recently, Rod Gullberg, said that breath labs that use the old air/water partition ratio could be miscalibrating their machines by as much as 2.5%.

We’ve seen the same story playing out over and over again with the state lab. They take shortcuts, fail to update their methods and produce indefensible results.

I’ve written extensively about the state alcohol lab’s problems, including:


The state crime lab will continue to produce results with flawed methods. The only way to fix the problems is to force them to fix them in court.

If you’ve been a victim of the state's faulty methods, you need a lawyer who understands the science.

Call Ramsay Law to analyze your case. We look at the science, and we get results.

Daniel Koewler