How does a breathalyzer work?

Published on: 2024-08-06      Views: 101

The working principle of the breathalyzer is mainly based on sensing technologies such as electrochemistry or infrared spectroscopy.

Take the electrochemical sensor as an example, when the subject exhales, the alcohol molecules in the gas produce a current change through the chemical reaction within the sensor, and the current change is proportional to the alcohol concentration. By measuring this current change, the amount of alcohol in the breath of the person being tested can be calculated. 

Infrared spectroscopy uses the absorption characteristics of alcohol molecules to specific wavelengths of infrared light, and calculates the alcohol concentration by measuring the change in light intensity.

They are two mainly working principles of alcohol tester machine.