How does a forensic toxicologist analyze a person's breath to determine alcohol levels?

How does a forensic toxicologist analyze a person's breath to determine alcohol levels?

Normally, in the United States and throughout the world, many people who are thought to be under the influence of alcohol while driving are tested at some point in the investigation with a breath-testing device. Now this test can come about at the time the automobile is stopped because many jurisdictions allow for portable breath-testing devices to be brought to the roadside. And an individual will blow into these devices and a number will be registered, and if that number is in excess, for example, of the per se level, which in the United States is 0.08 percent, that individual will then be brought back to the police station for further investigation. Now, at the police station, either a blood sample can be taken from the suspect for testing in the toxicological laboratory for alcohol content, or that suspect can be subject to a more comprehensive and sophisticated breath test. The breath test is a test that allows one to correlate the breath alcohol that is being measured with the blood alcohol level, and there is a correlation that is well-accepted in the legal community, and the result of a breath test will then be equivalent to the result of a blood test.