Currently, the State of North Carolina uses the EC/IR II breath test machine to prove DWI. In addition, police also use handheld breath testing devices, commonly known as PBT. Although the PBT results are not admissible in court, officers use them to develop probable cause to arrest. Because submitting to PBT is not required by law, it is generally advisable to refuse when offered.

breath testBreath Test Theory

In theory, the EC/IR II estimates blood alcohol from a sample of someone’s breath. In order to make this guess, the machine uses an infrared spectrophotometer. However, there are many potential problems with this process. For example, the machine treats everyone as the same. Rather, there are no adjustments for height, weight, sex, fever, or any other individual feature. Of course, alcohol affects everyone differently. Nevertheless, we are all the same for EC / IR II purposes.

Another problem is time of the breath test. Even if accurate, the reading only shows BAC when tested, not when driving on the road. While the law says BAC “at any relevant time,” we only care when someone is behind the wheel. Consequently, even if “above the legal limit” when tested, you could be “below 0.08” when it really matters.

Breath Test Procedure

So here is how testing actually works. Once brought into the breath test room, the officer checks your mouth and then waits 20 minutes. Why? Because you cannot have anything in your mouth and residual alcohol needs time to clear. Next, the machine makes a series of “accuracy” checks. Of course, the machine is actually testing itself (think HAL 9000). Finally, after the wait period, you give two breath test samples just minutes apart. Under NC law, the test results cannot be more than 0.02 different. Furthermore, your “reported” BAC is the lower of the two readings. While police claim the two tests are more fair, different readings just minutes apart is really an “inconsistent” result. Rather, only the State and the machine manufacturer truly believe in this breath test “science.”

If charged with a Charlotte DWI, contact our office immediately. Time is critical. For more information about our lawyers credentials and experience, click here. Then, for a private, confidential consultation, call 704-351-7979. And even if you need us in the evening or on the weekend, we are here. Call now.