How do breathalyzers work

Breathalyzers work by detecting the amount of alcohol in a person's blood. Any alcohol that a person drinks is not digested upon absorption. As the blood moves through the lungs, some of the alcohol evaporates, so when you exhale, the breathalyzer can detect the alcohol in your breath.
Updated on Friday, May 20 2011 at 06:48PM EDT
Source: electronics.howstuffworks.com/...