A breath test measures your blood alcohol concentration (BAC). Police are checking to see if drivers are over the legal limit, which is 0.08% for most people. Commercial and underage drivers are notable exceptions.
However, even if you fail a breath test, that does not necessarily guarantee that you will be convicted on impaired driving charges. There are some ways to challenge the results of that test.
Did the officer have the correct training?
First, perhaps the officer made a mistake while giving you the breath test. You may believe the results are not accurate, and you may not be sure the officer was properly trained to use the test. Errors by the police could invalidate the results.
Was the test properly calibrated?
It can also help to look at the maintenance and calibration records for that breath test device. If it has been kept up to date, then the accuracy can likely be trusted. However, if it has been neglected for a significant amount of time, there is no telling if it was properly calibrated and providing accurate results.
Did anything else influence the test?
Finally, certain factors can sometimes produce a higher reading, such as burping while taking a breath test or having residual alcohol in your mouth. If you only had half of a drink but registered as being over the legal limit, these types of factors could have artificially inflated the results.
These are just three potential areas to consider, but it is important to know that you can sometimes challenge your breath test. Be sure you know what legal defense options you have.