How does a fuel cell breathalyzer work to measure alcohol levels in a person’s breath?

A fuel cell breathalyzer measures alcohol levels in a person’s breath through a chemical reaction that takes place in the fuel cell sensor. The key steps in this process are as follows:

 

Sample Collection:

When a person exhales into the breathalyzer, a breath sample is collected.
Oxidation Reaction:

The collected breath sample is directed to the fuel cell sensor.
Within the fuel cell, the breath sample comes into contact with a porous anode, and oxygen from the air interacts with the anode.
Electrochemical Reaction:

Ethanol (the primary component in alcoholic beverages) in the breath undergoes an electrochemical oxidation reaction at the anode.
The reaction typically involves the conversion of ethanol to acetic acid, water, and the release of electrons.
Electric Current Generation:

The electrochemical reaction generates a flow of electrons. This flow of electrons constitutes an electric current.
Measurement of Electric Current:

The electric current produced is proportional to the amount of ethanol in the breath sample.
The fuel cell breathalyzer measures this electric current and converts it into a corresponding alcohol concentration reading.
Display of Results:

The alcohol concentration reading is then displayed on the breathalyzer’s screen, indicating the level of alcohol in the person’s breath.

Fuel cell sensors are known for their specificity to ethanol, the type of alcohol found in alcoholic beverages, which makes them suitable for accurately measuring blood alcohol concentration. They are commonly used in law enforcement and workplace settings due to their accuracy and reliability. Regular calibration and maintenance are essential to ensure the ongoing accuracy of a fuel cell breathalyzer.