How does the electrochemical fuel cell in the EC/IR II operate when exposed to alcohol?

How does the electrochemical fuel cell in the EC/IR II operate when exposed to alcohol?

• A. It measures the chemical content of the breath.
• B. It uses infrared energy absorption to detect alcohol.
• C. It relies on a color change in a reagent.
• D. It creates electrical voltage when it comes into contact with alcohol.

Answer: (D)

In an electrochemical fuel cell sensor, alcohol in the breath is oxidized at the sensor’s electrode, and this chemical reaction releases electrons. Those electrons flow through the circuit, producing a current (or voltage) that the instrument measures. The size of that electrical signal is proportional to how much ethanol is present, so the device converts it into a breath alcohol concentration reading. This differs from infrared-based detectors or color-change tests, which rely on light absorption or visible reagent changes rather than generating an electrical signal from an oxidation reaction.

In an electrochemical fuel cell sensor, alcohol in the breath is oxidized at the sensor’s electrode, and this chemical reaction releases electrons. Those electrons flow through the circuit, producing a current (or voltage) that the instrument measures. The size of that electrical signal is proportional to how much ethanol is present, so the device converts it into a breath alcohol concentration reading. This differs from infrared-based detectors or color-change tests, which rely on light absorption or visible reagent changes rather than generating an electrical signal from an oxidation reaction.