What principle does infrared spectroscopy utilize in the Intoxilyzer 9000?

The Intoxilyzer 9000 employs infrared spectroscopy based on the principle of measuring the absorption of infrared light specific to ethanol molecules. In this process, a sample of the breath is passed through a chamber where infrared light is emitted and directed through it. Ethanol, like many molecules, has specific wavelengths of light that it absorbs. When breath containing ethanol is present, the infrared light will be absorbed at these specific wavelengths, correlating to the concentration of ethanol in the breath sample. The device measures how much light is absorbed, allowing it to quantify the amount of ethanol within the breath.

This method is particularly effective because it allows for a non-invasive and quick assessment of alcohol levels in the bloodstream via breath analysis, making it a valuable tool for law enforcement and breath testing protocols. The selectivity of infrared spectroscopy ensures that other components of the breath do not interfere significantly with the measurement of ethanol, further enhancing the accuracy of the results.