Accuracy of Breathalyzers in Virginia

A potential client and their attorney could argue the accuracy of breathalyzers in Virginia during trial. They can argue that the machine is designed to detect a circumstance called residual mouth alcohol. Residual mouth alcohol is where a person has recently had alcohol in their mouth and that alcohol has settled into the soft tissues in their mouth. This means, the alcohol has been absorbed into their cheeks and gums and tongue and so forth. If you are have been asked to submit a breath sample or blood test for the investigation of your drunk driving charge, contact a distinguished DUI lawyer who can present your defense on your behalf.

Functionality of a Breathalyzer

If the machine detects that irregularity of the curve, it is supposed to reject the sample. However, that function of the machine does not always work and many experts have tested it while intentionally introducing mouth alcohol to the equation and found that it produces a valid result, even though it should not have.

Breathalyzers in Virginia do not take air temperature into account. If someone has a fever, their BAC is going to be artificially inflated. The machine has the capability of detecting the air temperature but the Virginia DFS has elected not to utilize that function. If an attorney can establish, at court, that the person was running a fever as they were administered that test, they could have an expert come to court and testify that the elevated body temperature would result in an elevated BAC.

Defining Partition Ratio

When looking at results of breathalyzers in Virginia, the machine will say that a person has X alcohol per 210 liters of breath. That ratio has to do with the partition ratio, which is a division of different types of blood cells in the blood. Any person walking down the street might have a partition ratio of 1800:1 or 2400:1, but the machine is settled on 2100. That is what they measure against and it is probably close to reliable, but it certainly is not perfect. It is nearly impossible to know someone’s partition ratio without testing their blood. This entire test is based on an assumption that can vary widely, and if a person’s partition ratio is off by enough, then the BAC level would be off by a considerable amount. It makes that assumption and the result is only going to be as good as the assumption which is not 100 percent reliable. In close cases where a person registers 0.08, an attorney can present evidence from an expert to show the unreliable issues.

Contacting a Lawyer

If you are facing drunk driving charges and have been asked to submit to a breathalyzer or BAC test, it may be critical to contact an experienced attorney regarding your case. A lawyer can compile the facts of your case and help protect your rights by defending against the accuracy of breathalyzers in Virginia by trying to discredit the machine itself. It is important to have legal representation who can help you disqualify harmful evidence.