BAT Result Interpretation & Analysis 2 — Questions and Answers
Question 1: A subject's BrAC result is 0.079 g/210L. Which statement is correct?
- The subject is legally impaired in all U.S. jurisdictions
- The result is below the 0.08 per se limit but may still indicate impairment (Correct answer)
- The test must be repeated because the result is too close to the limit
- The result should be rounded up to 0.08 for reporting purposes
Correct answer: The result is below the 0.08 per se limit but may still indicate impairment
0.079 is below the 0.08 g/210L per se limit, but impairment can exist at any BrAC level.
Question 2: What does a 'slope detector' on an evidential breath testing instrument detect?
- Mouth alcohol rapidly declining during the sample plateau (Correct answer)
- The angle of exhalation by the subject
- Residual alcohol from a previous test
- Ambient air contamination from the surroundings
Correct answer: Mouth alcohol rapidly declining during the sample plateau
The slope detector identifies mouth alcohol by sensing a rapidly falling alcohol concentration that does not plateau during the breath sample.
Question 3: When two sequential breath results differ by more than 0.020 g/210L, the correct action is to:
- Average the two results and report the mean
- Report the lower of the two results
- Void the test and conduct a new breath alcohol test sequence (Correct answer)
- Report the higher result as the official BrAC
Correct answer: Void the test and conduct a new breath alcohol test sequence
A difference exceeding 0.020 g/210L between duplicate samples invalidates the test sequence and requires retesting.
Question 4: Which physiological factor can cause a falsely elevated BrAC reading on a breath test?
- Hyperventilation immediately before the test
- Hypoventilation or breath-holding before the test (Correct answer)
- Consuming a high-fat meal shortly before testing
- Exercising vigorously one hour before the test
Correct answer: Hypoventilation or breath-holding before the test
Hypoventilation or breath-holding allows alveolar air to become more concentrated with alcohol, raising the BrAC reading above actual blood alcohol.
Question 5: The Henry's Law partition ratio used in evidential breath testing assumes a blood-to-breath ratio of:
- 1700:1
- 2100:1 (Correct answer)
- 2300:1
- 1:2100
Correct answer: 2100:1
Evidential breath testing instruments use a 2100:1 blood-to-breath partition ratio to convert BrAC to an equivalent blood alcohol value.
Question 6: A subject with gastroesophageal reflux disease (GERD) is being tested. The BAT should:
- Proceed normally as GERD has no effect on breath results
- Be aware that regurgitation could introduce mouth alcohol and invalidate the test (Correct answer)
- Use a blood draw instead since GERD makes breath testing impossible
- Double the observation period to 40 minutes to account for GERD
Correct answer: Be aware that regurgitation could introduce mouth alcohol and invalidate the test
GERD can cause regurgitation of stomach contents containing alcohol, potentially introducing mouth alcohol and inflating the BrAC result.
Question 7: Which condition would cause the evidential breath test device to display an 'INVALID SAMPLE' or similar error?
- The subject exhales for exactly 6 seconds
- The subject's breath does not meet minimum flow or volume requirements (Correct answer)
- The ambient temperature is 70°F (21°C)
- The result is below 0.020 g/210L
Correct answer: The subject's breath does not meet minimum flow or volume requirements
Insufficient exhalation flow or volume prevents the instrument from obtaining a valid deep-lung (alveolar) air sample.
BAT Result Interpretation & Analysis 2
A subject's BrAC result is 0.079 g/210L.
Which statement is correct?