Two samples must be within how many BAC units of each other?

Two samples must be within how many BAC units of each other?

• A. 0.01
• B. 0.05
• C. 0.10
• D. 0.02

Answer: (D)

A reading should be consistent enough to be trustworthy, so the test uses a small but reasonable tolerance between two readings. A difference of 0.02 BAC units accounts for normal instrument variability, slight operator differences, and minor environmental effects without letting large discrepancies go unchecked. If two readings differ by more than this amount, the result isn’t reliable and the test should be repeated or the device recalibrated. For example, with a BAC around 0.08, acceptable readings would range from 0.06 to 0.10. Tolerances much smaller than 0.02 would be too strict given typical measurement noise, while larger tolerances could mask inaccuracies. Hence 0.02 BAC units is the appropriate standard.

A reading should be consistent enough to be trustworthy, so the test uses a small but reasonable tolerance between two readings. A difference of 0.02 BAC units accounts for normal instrument variability, slight operator differences, and minor environmental effects without letting large discrepancies go unchecked. If two readings differ by more than this amount, the result isn’t reliable and the test should be repeated or the device recalibrated. For example, with a BAC around 0.08, acceptable readings would range from 0.06 to 0.10. Tolerances much smaller than 0.02 would be too strict given typical measurement noise, while larger tolerances could mask inaccuracies. Hence 0.02 BAC units is the appropriate standard.