In Texas, there are three kinds of blood alcohol content tests that may be used to prove a DWI. These include urine tests, blood tests and Breathalyzer tests.
Out of these, the most commonly used is the Breathalyzer test. However, other chemical tests, such as the urine or blood tests, may be used in some circumstances. Which one is most accurate? That depends on the circumstances, but generally speaking, blood tests are the most accurate.
What should you know about the three kinds of BAC tests?
The first thing to know is that you can be asked to provide a blood sample, urine sample or breath sample if an officer believes that you’re impaired. Of those three, the blood sample is most accurate, but lab errors can still occur. This test may be ordered if you refuse to take a Breathalyzer test at the scene of a stop.
The next option is the urine test, which is not as accurate as the Breathalyzer or blood tests. Urine tests are considered intrusive, so they are usually only ordered once a person refuses a Breathalyzer test. The urine test is less accurate, because alcohol may remain in a person’s urine for up to 24 hours after drinking. It’s possible for the BAC result to come back too high or too low. Either way, these tests are more likely to be inaccurate.
Finally, the common Breathalyzer test is usually used during traffic stops. This test is taken with a Breathalyzer, which collects and analyzes a sample. The machine measures how much alcohol is passing through the alveoli air sacs of the lungs. It’s important for officers to take at least two tests and for those tests to be within a tight margin of error. If they are too far off, then your attorney could argue that the machine was not calibrated correctly or that the tests were simply inaccurate.
After any kind of traffic stop where you’re accused of a DWI, know that you have the right to argue against the test results. Mistakes are made, and it is possible that the tests were inaccurate.