!9# Alcohol Testing Methodology - Breathalyzer, Blood Testing, Etc

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There are various methods available for testing of alcohol. Alcohol in the blood, breath, urine and saliva can be tested.

Blood-alcohol test

Alcohol concentration (BAC) is a standard to measure the degree to which an individual is impaired by alcohol. For years, studies have shown a direct correlation between the concentration of alcohol in the blood and the degree of the reactions and decisions are compromised. The methodologyblood alcohol test is gas chromatography and is the most accurate test as in forensics. However, blood sampling is invasive and expensive that prevent most companies prefer.

Alcohol Breath Test

There is evidence that there is a direct correlation between the concentration of alcohol in a person's blood and breath alcohol content. During breathing, the gas from the lungs to the blood replaced (primarily oxygen) during inhalation, andvice versa (primarily C02) during exhalation. During this exchange, the alcohol evaporates and is carried in the blood from the lungs into the air. There are different types of alcohol breath tester on the market. These range from disposable screening testers to the equipment, the results legally admissible, even very expensive breath alcohol reading of digital monitor provides. These types of testers are divided into three categories:

Breath alcohol measuring devices NotProbationary portable devices Disposable devices (does not provide forensic results)
The breath alcohol measuring devices are generally expensive (costing $ 2000 - $ 5000 per unit), require regular maintenance, repair and calibration, and must be operated by certified personnel. Attachments such as sterile mouth pieces must each time a test is performed. These units are great tabletop unit designed to be used in one place. Movement can cause a change in the calibrationrequiring maintenance.

Mobile devices provide results accurate enough and are used for screening purposes. By measuring the alcohol content in exhaled air, a reliable indication is obtained for the concentration of alcohol in the blood. The portable devices are less accurate than probative, however, comparing the cost-performance ratio, these devices are cheap and adequate for personal use. Most of the devices of drinking water are not conclusive and can not therefore be usedthe court.

The disposable non-invasive, non-scalable and less accurate methods of screening for alcohol. It can be used to detect the presence of alcohol with a rough estimate of the degree of impairment. As disposable, the cost per test for preliminary screening are significantly higher than the cost of portable test equipment.

That's how they work, the ethyl alcohol in the blood escapes through the lungs into the air. The presence of ethylThe alcohol in the breath is detectable by a color change of very sensitive chemically coated crystals disposable breath analyzer content. Immediately before use, the ampule with gentle finger pressure on the outer surface of the hose pulled clear crystals within the boundaries of the release tube. When the subject exhales into the tube, the crystals to interact with the steam of breath and change color from yellow to blue, if alcohol is present. When all the crystals change color completely, thisindicates that the concentration of blood alcohol is 0.10% with respect to the subject, above the legal limit in many states.

Alcohol Urine Test

Although alcohol urine test will be the presence of alcohol by a person, not give the current status of the person. After consuming alcohol enters the bloodstream through the stomach in 15 minutes, causing immediate damage. And 'then absorbed by the body, and after 1 ½ to 2 hours, begins to show inUrine. Therefore, alcohol is not measured in the urine a true condition of the person. The results demonstrate against the state for several hours.

Additionally, urine alcohol concentration does not directly correspond to the concentration of alcohol in the blood. Alcohol concentration in the urine depends on the human metabolism and the amount of fluid in his system. For example, a person who is slightly dehydrated tend to have a higher concentration of alcohol in the urine of those whoa normal level of fluid in his system.

At least one study has shown that a false positive for alcohol in urine may occur. High concentrations of sugar and acetone in the body can cause fermentation in the urine, resulting in false positive for alcohol in urine. All in all, the urine-alcohol test or have preferred less accurate test available for alcohol testing. It is worthwhile to read a work of scientific support published in the Journal of Clinical Pathology: ERRORThe conversion of a value ALCOHOL IN URINE a blood alcohol level. SIDNEY KAYE, Ph.D., and Eduardo Cardona, MS

Saliva Alcohol Test

The second type of disposable tester available today tests the saliva for the presence of alcohol. Although a correlation between the concentration of alcohol in the blood and saliva alcohol concentration is assumed, has the technology and the chemical reaction can be used, has not been proven accurate and reliable.

Tester saliva are treated with an enzymeOxidize the alcohol, which reacts with alcohol in relation to the concentration of alcohol in a saliva sample mixture placed on it. The user estimates the BAC standard colors are calibrated to correspond to different BAC by comparing the change of color patches on the strip.

Although some saliva testers the presence of alcohol fairly good point, the enzyme oxidizes alcohol in these devices is comfortable with hot and cold temperatures. High temperatures will tend to emphasizefalsely elevated values, while cold temperatures tend to indicate falsely low readings. Exposure to temperatures above 80 degrees Celsius or ambient air leads to the destruction of alcohol enzyme oxidizes obviating the tester. Most saliva testers give no indication of whether the contamination occurred, it will not work. Saliva testers generally have a duration of one year or less.

In addition, most of the testers saliva test results by independent laboratories.