DWI Breath Testing In Texas
n Texas, when a person is arrested for Driving While Intoxicated, the police will normally ask for the suspect to submit a breath sample on a device that is called the Intoxilyzer 5000. The device purports to measure a person's alcohol concentration in breath, and express it in terms of grams of alcohol per 210 liters of breath. The legal limit in Texas is 0.08 grams of alcohol per 210 liters of breath.
The technology employed by the Intoxilyzer 5000 is known as infrared spectroscopy. Basically, the breath sample is forced through a chamber and into the path of an infrared beam of light.
When a person submits to a breath test using an Intoxilyzer 5000, the person still has a chance to prevail at trial, depending upon the specific facts of the case. However, the fact of the breath test is a piece of evidence available to the prosecutor that might not otherwise be available in the absence of a breath test.
At the Law Office of Derk A. Wadas, we will exploit any weakness in the Intoxilyzer 5000 evidence to our client's advantage. Some of the evidentiary issues involving the breath testing machine are . . . .
The Intoxilyzer 5000 can only measure the person's alcohol concentration at the time the test is taken. The machine cannot measure the person's alcohol concentration at the time of driving. The law requires that in order to convict someone of DWI, the prosecutor must prove intoxication at the time of operation.
Frequently, I am asked questions about blood alcohol concentration and breath alcohol concentration as though the two are interchangeable. The Intoxilyzer 5000 is incapable of measuring a person's blood alcohol concentration. Because it is the alcohol in a person's bloodstream that causes intoxication, the Intoxilyzer 5000 assumes a relationship between the alcohol concentration is a person's blood and the alcohol concentration in person's breath. This assumed relationship is what is known as the Partition Ratio.
The Partition Ration however, is an assumed breath/blood relationship and does not take into account individual variability. The science shows that in a given population, the partition ration for a given person can vary widely.
Interfering Substances
Residual Alcohol
Residual Alcohol is, roughly speaking, alcohol from the mouth. The Intoxilyzer is designed to measure deep lung air, known as alveolar air. Residual alcohol may be wildly out sync with the alveolar air. The Intoxilyzer 5000 may be incapable of distinguishing between residual alcohol and alveolar air.
Specimen Duration
Generally speaking, the longer a person blows into the machine, the higher the recorded alcohol concentration will be.
Breath Temperature
The Intoxilyzer 5000 is calibrated and the calibration is checked with sample solutions that are heated to 34 degrees celsius. A higher human body temperature will increase the alcohol concentration.
The above are a few example of the sorts of deficiencies that are inherent in the Intoxliyzer 5000
The technology employed by the Intoxilyzer 5000 is known as infrared spectroscopy. Basically, the breath sample is forced through a chamber and into the path of an infrared beam of light.
When a person submits to a breath test using an Intoxilyzer 5000, the person still has a chance to prevail at trial, depending upon the specific facts of the case. However, the fact of the breath test is a piece of evidence available to the prosecutor that might not otherwise be available in the absence of a breath test.
At the Law Office of Derk A. Wadas, we will exploit any weakness in the Intoxilyzer 5000 evidence to our client's advantage. Some of the evidentiary issues involving the breath testing machine are . . . .
The Intoxilyzer 5000 can only measure the person's alcohol concentration at the time the test is taken. The machine cannot measure the person's alcohol concentration at the time of driving. The law requires that in order to convict someone of DWI, the prosecutor must prove intoxication at the time of operation.
Frequently, I am asked questions about blood alcohol concentration and breath alcohol concentration as though the two are interchangeable. The Intoxilyzer 5000 is incapable of measuring a person's blood alcohol concentration. Because it is the alcohol in a person's bloodstream that causes intoxication, the Intoxilyzer 5000 assumes a relationship between the alcohol concentration is a person's blood and the alcohol concentration in person's breath. This assumed relationship is what is known as the Partition Ratio.
The Partition Ration however, is an assumed breath/blood relationship and does not take into account individual variability. The science shows that in a given population, the partition ration for a given person can vary widely.
Interfering Substances
Residual Alcohol
Residual Alcohol is, roughly speaking, alcohol from the mouth. The Intoxilyzer is designed to measure deep lung air, known as alveolar air. Residual alcohol may be wildly out sync with the alveolar air. The Intoxilyzer 5000 may be incapable of distinguishing between residual alcohol and alveolar air.
Specimen Duration
Generally speaking, the longer a person blows into the machine, the higher the recorded alcohol concentration will be.
Breath Temperature
The Intoxilyzer 5000 is calibrated and the calibration is checked with sample solutions that are heated to 34 degrees celsius. A higher human body temperature will increase the alcohol concentration.
The above are a few example of the sorts of deficiencies that are inherent in the Intoxliyzer 5000