Answer to Question 1
A fuel cell detector converts alcohol in alveolar breath into acetic acid, generating an electrical current that is proportional to the quantity of alcohol present in the breath. The stronger the current, the greater the concentration of alcohol in the subject's breath.
Answer to Question 2
Mouth alcohol is alcohol present in a breath-test subject's mouth. The presence of mouth alcohol can cause the alcohol concentration detected in exhaled breath to be higher than the actual concentration in the blood. Potential sources of mouth alcohol include regurgitation, belching, recent intake of an alcoholic beverage, and recent gargling of an alcohol-containing mouthwash.
