Which instrument is used to measure the Blood Alcohol Content (BAC) from a person's breath?

Which instrument is used to measure the Blood Alcohol Content (BAC) from a person's breath?

• A. Breathalyzer
• B. Breath Test Device
• C. Alcohol Analyzer
• D. Breathing Meter

Answer: (A)

Measuring BAC from breath relies on analyzing the amount of alcohol in the exhaled air, which mirrors the alcohol in the blood due to the blood–breath equilibrium. The instrument used for this is the Breathalyzer. It detects ethanol in the breath—using a chemical reaction, a fuel-cell sensor, or infrared technology—and then converts that breath concentration into an estimated blood alcohol concentration, usually shown as a percentage (like 0.08%). The key idea is that the breath sample provides a reliable proxy for blood alcohol because the alveolar air reflects the alcohol level in the bloodstream, with a standard ratio used to translate breath alcohol into BAC. While other names exist in casual language, the Breathalyzer is the established device widely recognized for roadside BAC testing.

Measuring BAC from breath relies on analyzing the amount of alcohol in the exhaled air, which mirrors the alcohol in the blood due to the blood–breath equilibrium. The instrument used for this is the Breathalyzer. It detects ethanol in the breath—using a chemical reaction, a fuel-cell sensor, or infrared technology—and then converts that breath concentration into an estimated blood alcohol concentration, usually shown as a percentage (like 0.08%). The key idea is that the breath sample provides a reliable proxy for blood alcohol because the alveolar air reflects the alcohol level in the bloodstream, with a standard ratio used to translate breath alcohol into BAC. While other names exist in casual language, the Breathalyzer is the established device widely recognized for roadside BAC testing.