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From: Robert Swotinsky MD
Password: orange
Date: 14 Dec 2006
Time: 13:45:49 -0800
Remote Name: 4.154.235.217
Thank you Dr. CRZ for recognizing the real issue here!
An external calibration test should be performed periodically according to the manufacturer's quality assurance plan (QAP). A manufacturer's QAP typically calls for monthly external calibration. Many breath alcohol technicians perform an external calibration test after each positive test result to ensure the validity of the individual test and to minimize the area for discrepancy. This is not required under the DOT Part 40 rule, and while a discrepant post-positive external calibration test is reason to cancel a result, the absence of a post-positive external calibration test is not identified by DOT as a reason to cancel a result. (See 49 CFR 40.267) In the case posted on this web site, no next calibration check was performed after the confirmation test. There's no "rule" governing this situation. I guess I'd want to know how recent the last calibration check took place, what the alcohol test level was, and how often and for how long the EBT had been calibrated and demonstrated good performance. If this EBT has been calibrated every month for a long time and always performed in a narrow range, that would support the test. If the EBT had been calibrated infrequently and had failed a number of times, that would raise doubt. So, while the absence of the post-test calibration is disappointing, it does not necessarily and completely negate the test's forensic integrity. Also, it the guy's BAC was high, e.g., 0.12 or 0.15, we'd have to assume an awful lot of variability to create a range of values that extends below 0.04.