The specific PAS model used in Orange County is the Alcotest 7410, manufactured by Draeger Safety, Inc., in Lubeck, Germany. This handheld device measures ethyl alcohol in the breath by oxidyzing it in a fuel cell, thus generating a small electrical current which is measured over a given time period; the more alcohol in the breath sample, the greater the oxidation, the more current generated and the higher the reading.
Besides the relatively primitive fuel cell technology, one of the main problems with the PAS units is their lack of technology for dealing with a number of problems in breath alcohol analysis. "Interferent detectors" -- used to detect the presence of chemicals which the device may mistakenly report as "alcohol" -- are not to be found in the PAS devices. Radio frequency interference (RFI) from such sources as police car or handheld radio transmitters, can also affect readings; unlike the evidentiary breathalyzers, the PAS units only have primitive RFI detectors, which work to some degree but only within a few feet of the source of interference.
Perhaps most importantly, there is no "mouth alcohol detector". If there is alcohol in the mouth which is breathed into the device, the reported blood alcohol concentration will be greatly increased, as the device's computer is programmed to assume that it has been metabolized in the body and is coming from the lungs. Unmetabolized alcohol in the mouth can come from a number of sources: recent ingestion of an alcoholic beverage; mouthwash or breath fresheners (most contain alcohol); burping or belching; teeth or dentures trapping food containing alcohol; acid reflux; And once in the mouth or throat, the alcohol can stay there for 15 minutes or longer -- and breathed directly into the PAS device undetected.
The Human Body and Alcohol
How alcohol is absorbed and metabolized, and the physical and mental effects.
Breath Analysis
A professor of pharmacology discusses the science of breath testing for alcohol.
California Drunk Driving Law
Extensive resource for legal and scientific aspects of DUI, including blood and breath alcohol analysis. |
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Breath Machines
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Copyright 2001 - 2008
Site Map | Legal Disclaimer
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The information provided by "Orange County DUI" is to offer assistance to those charged with driving under the influence. The resources are also provided to oppose the viewpoints of those striving for impractical DUI laws, the return of prohibition, and the reduction of our constitutional rights. The National Motorists Association joins the struggle against these viewpoints by stating their views on other DUI topics, such as unconstitutional checkpoints, license revocations, inappropriate penalties, and inaccurate field sobriety tests.
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