How is breath testing done?
Breath tests in Texas are done by a machine known as an Intoxilyzer 5000. Breathalyzers are not used. The Intoxilyzer machine, which costs approximately $7,500.00, is said to work on the principle of infrared spectrometry. According to its manufacturer and the Texas Department of Public Safety (DPS), which certifies and writes the rules for its use, the machine determines alcohol concentration by subtracting the amount of light absorbed from the person’s breath sample and then comparing that amount to the amount of light originally introduced into the breath sample the difference is the test result.
