 |
 |
 |
 |
|
 |
How Does A Breathalyser Work for DUI in Upper Marlboro?Since it is a physiological response, the partition ratio can be raised or lowered by: Body Temperature: The widely used blood-to-air partition ratio of 2100 is based on a normal body temperature of 98.6°F. A higher body temperature of the individual will overestimate the actual BAC because of the higher volatility (or vapor pressure) of liquids like alcohol at a higher temperature. An elevation in body temperature of 1°C (1.8°F) results in a 7% higher value in the result. Therefore, a person with a body temperature of 100.4°F, and with an actual blood alcohol of 0.0935%, will register a value of 0.10% by the breath test. Be careful if you have a cold or the flu. Cellular Composition Of Blood: Blood contains suspended cells (e.g. red and white cells) and proteins, and is therefore only a partial liquid. The partition ratio of 2100 is based on an average cell volume of blood of 47%. Cell volume values range from 42 to 52% in males and 37 to 47% in females. Therefore, a person with a lower cell volume will have a falsely elevated blood alcohol based on a breath test, however this variability has been estimated to be relatively small, ranging from - 2 to + 5%. In most countries the partition ratio is presumed to be 2100:1 unless the defendant presents evidence that his/her personal ratio should be reasonably be assumed to be significantly higher or lower. What Are Field Sobriety Tests for DUI in Upper Marlboro? Field Sobriety Tests (FST's) are psychophysical tests used to assess a person's physical and/or mental impairment. They focus on the abilities needed for safe driving. Most of the more reliable psychophysical tests are known as "divided attention" tasks. They require a person to concentrate on more then one task at the same time. To safely drive a car, a person needs to be able to simultaneously control steering, breaking, and acceleration; react to constantly changing driving environment; and perform many other tasks. Alcohol affects one's ability to adequately divide attention, thus causing drivers to concentrate on more difficult tasks while ignoring simpler ones (i.e. ignore a traffic signal while concentrating on one's speed). Even if impaired, most people can successfully concentrate on a single task fairly well, but when impaired, most drivers cannot successfully divide their attention between multiple tasks at once. Divided attention tasks are designed to evaluate mental and physical capabilities a person needs to safely drive a car. They include information processing; short-term memory; judgment and decision making; balance; steady, sure reactions; clear vision; small muscle control; and coordination of limbs. A good FST will combine any two or more of these capabilities simultaneously. A test must also be reasonably simple for the average non-intoxicated person to perform. The most common FST's for DUI in Upper Marlboro used by the police include the three standardized tests consisting of the Horizontal Gaze Nystagmus tests, Walk and Turn, and the One Leg Stand test. These three tests have been validated as reliable indicators of intoxication, although they are not 100% accurate. Other commonly used, but non-standardized, tests for DUI in Upper Marlboro include counting backwards, saying the alphabet (or a portion of it), finger count, and the stationary balance (Rhomberg) tests. In reference to the three standardized FST's, the government has admitted, and it is printed in the police officers DWI manual, that "IT IS NECESSARY TO EMPHASIZE THIS VALIDATION ONLY APPLIES WHEN: THE TESTS ARE ADMINISTERED IN THE PRESCRIBED STANDARED MANNER; THE STANDARDIZED CLUES ARE USED TO ASSESS THE SUSPECTS PERFORMANCE; THE STANDARDIZED CRITERIA ARE EMPLOYED TO INTERPRET THAT PERFORMANCE. IF ANY ONE OF THE STANDARDIZED FIELD SOBRIETY TEST ELEMENTS IS CHANGED, THE VALIDITY IS COMPRAMISED." |
|