Final answer:
To determine a person's blood alcohol concentration (BAC), information such as age, sex, weight, and health conditions is needed, combined with the measurement of how alcohol is metabolized in their body. Breathalyzers and blood tests are common methods of measuring BAC, with the legal limit typically being 0.08% for driving. Additional assessments like the Field Sobriety Test can indicate alcohol influence but do not measure BAC directly.
Step-by-step explanation:
To determine a person's blood alcohol concentration (BAC), various pieces of information are necessary. A BAC can vary depending on several factors, including a person's age, sex, weight, and pre-existing health conditions. The rate at which alcohol is metabolized in the body plays a crucial role in determining BAC. On average, the liver breaks down alcohol at a rate of about 3.3 mmol/L (15 mg/dL) per hour. However, it's important to note that women generally metabolize alcohol more slowly than men, and individual metabolic rates can vary by 25-30%. In legal and medical contexts, BAC is often measured through blood tests or breath analysis using devices such as a Breathalyzer, which relies on the oxidation of ethanol to determine alcohol levels.
Since the effects of alcohol differ widely between individuals, a Breathalyzer test or a blood test would provide an empirical method for determining BAC. The Breathalyzer specifically measures the ethanol concentration in a person's breath, which correlates with the blood alcohol level. This device's reaction involves the oxidation of ethanol, resulting in a color change in the reaction solution, providing an estimate of the BAC. The legal limit for driving under the influence typically stands at a BAC of 0.08% in the United States.
Furthermore, the Field Sobriety Test (FST) assesses motor coordination and balance influenced by the cerebellum, which is especially sensitive to ethanol. While this test is not a direct measure of BAC, it helps in assessing if a person is under the influence of alcohol.