Breath Tests for Alcohol Are Not Perfect
If a person is arrested on suspicion of driving under the influence of alcohol, the Breathalyzer results may be used by prosecutors in a DUI case.
October 11, 2012
In 2011 the state of Washington began changing over the machines its law enforcement officers use to determine the blood alcohol content of people suspected of driving drunk. Commonly referred to as Breathalyzers, these machines use a breath test to measure how much alcohol is in a person's system. If a person is arrested on suspicion of driving under the influence of alcohol, the Breathalyzer results may be used by prosecutors in a DUI case.How Breathalyzers Work
After a person ingests alcohol, the alcohol enters the bloodstream from the stomach without undergoing chemical changes. The flowing blood picks up inhaled oxygen from tiny sacs that make up the lungs, where these sacs in turn take up some of the alcohol from the blood in gaseous form. The gaseous alcohol is then exhaled through normal breathing.
Breathalyzers analyze the exhaled breath and determine how much alcohol is in the sample, and then calculate what percentage of alcohol is in the bloodstream. One type of device works by bubbling a breath sample through a chemical mixture. A chemical reaction with alcohol causes a color change, which is measured and interpreted as the level of alcohol in the breath sample, then recalculated to indicate the associated level of alcohol in the blood. A needle on the machine display will move, and the operator has to turn a knob to get a proper reading.
Another type of breath test machine works by analyzing light as it passes through a breath sample. Different materials absorb light in different ways, and the device detects the kind of light absorption associated with alcohol and measures how much light is absorbed to arrive at an amount of alcohol.
Results Not Fool-proof
The results obtained by these machines are often used by prosecutors as evidence in DUI cases. The evidence is not always rock-solid, however. Whatever the type of machine, it is no better than its operators, who must know both how to calibrate the device and how to administer tests. Officers who are not properly trained can make mistakes leading to inaccurate results. In addition, the devices must be tested for quality assurance once a year. Because of these opportunities for error, in the past, Washington defense lawyers have successfully challenged some Breathalyzer test results.
An experienced defense attorney is invaluable for anyone who has been accused of impaired driving and given a Breathalyzer test. An attorney will know the possible bases for challenging test results and will help protect the accused driver's rights.
Article provided by The Law Offices of Smith and White, PLLC
Visit us at http://www.duilawyertacomawa.com/