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How does a breathalyzer measure blood alcohol levels?

On Behalf of | Jun 9, 2023 | Drunk Driving Charges, DUI and DWAI Charges |

It is standard operating procedure to have a driver suspected of driving under the influence of alcohol to blow into a Breathalyzer operated by the officer. Still, it makes one wonder how one’s breath measures their blood alcohol level, particularly if they have recently had to do it. Would it make more sense to have the driver walk in a straight line, which would indicate impaired fine motor skills?

The science explained

According to scientists, alcohol consumed while drinking is ethanol, which is a water-soluble compound. It passes through the walls of the digestive system – the process is called passive diffusion. Once through the walls, the ethanol molecules enter the circulatory system and pass throughout the body, making it to the lungs. The molecules vaporize when they encounter oxygen in the lungs, and the subsequent gas exits by breathing.

Corrective equilibrium

The vaporization of ethanol molecules continues until none are in the body. Technically, each breath lowers the BAC in the blood to maintain equilibrium. Some advise that it is better to wait for a blood test or at least challenge the results of that Breathalyzer test, which are less reliable.

Some may still have questions

Of course, it’s also crucial to remember that a Breathalyzer is a sensitive device that must be expertly operated and maintained for optimal results. Officers who fail to do this may not have the accurate reading they claimed during the arrest. Those who have questions about their DUI case may find that the prosecution’s evidence is not as strong as it claims.