A DataMaster/breath alcohol test determines how much alcohol is in your blood by measuring the amount of alcohol in the air you breathe out (exhale).
What can affect your BAC?
- Quantity of alcohol.
- How fast you drink, e.g. speed of consumption. In general, the quicker you drink, the higher your peak BAC will be.
- Body size. Given the same amount of alcohol consumption, larger people tend to reach lower BACs than smaller people.
- Food in your stomach. When there is food in your stomach, alcohol is absorbed more slowly into the blood stream. The BAC rises more rapidly when you drink on an empty stomach, because there is no food in which to dilute the alcohol.
- Type of mixer used. Carbonated mixers and beverages speed up the absorption of alcohol. Water and fruit juices mixed with alcohol may slow the absorption process.
- Women reach higher BACs faster because they have less water in their bodies and more adipose tissue (fat), which is not easily penetrated by alcohol.
- All other factors being equal, if a man and a women both drink the same amount of alcohol, the women will have a higher breath/alcohol content.
Falsehood: Police Officers can use field sobriety tests, which are based on scientific principles, to accurately identify intoxicated drivers.
Truth: A study conducted by scientists at Clemson University involved showing police officers videotapes of individuals taking six common field sobriety tests. The officers were asked to decide whether suspects were too intoxicated to drive legally. Unknown to the officers, none of the suspects had consumed any alcohol and they all had breath/alcohol levels of .000. They had zero alcohol in their blood. However, in the professional opinion of the officers, 46% of the completely sober individuals were too drunk to drive! Therefore, use of field sobriety tests led to judgments by law enforcement officers that were about as accurate as flipping a coin.
Falsehood: Police and other law enforcement officers can’t influence the BAC reading of a breath-testing machine.
Truth: Law enforcement officers can and do influence BAC readings. Law professor and lawyer Lawrence Taylor quotes Dr. Michael Hlastala, Professor of Physiology, Biophysics and Medicine at the University of Washington found, “By far, the most overlooked error in breath testing for alcohol is the pattern of breathing…. The concentration of alcohol changes considerably during the breath…The first part of the breath, after discarding the dead space, has an alcohol concentration much lower than the equivalent BAC. Whereas, the last part of the breath has an alcohol concentration that is much higher than the equivalent BAC. The last part of the breath can be over 50% above the alcohol level….Thus, a breath tester reading of 0.14% taken from the last part of the breath may indicate that the blood level is only 0.09%.”
Professor Taylor explains that “Many police officers know this. They also know that if the machine contradicts their judgment that the person they arrested is intoxicated, they won’t look good. So when they tell the arrestee to blow into the machine’s mouthpiece, they’ll yell at him, “Keep breathing! Breathe harder! Harder!” As Professor Hlastala has found, this ensures that the breath captured by the machine will be from the bottom of the lungs, near the alveolar sacs, which will be richest in alcohol. With the higher alcohol concentration, the machine will give a higher – but inaccurate reading.”
MICHIGAN’S NEW DATAMASTER DMT
In Michigan, there is a new breath/alcohol testing machine that is now being used by law enforcement, the DataMaster DMT. The DataMaster uses an infrared light source to measure the amount of alcohol in a breath sample
The old DataMaster and the new DataMaster DMT measure breath alcohol by employing the principle of absorption of infared energy. DMT means “DataMaster Transportable.” The DataMaster DMT is faster, has a more powerful processer, and can be transported to the scene of an alleged OWI/Operating While Intoxicated.
In Michigan, police are supposed to observe a test subject for 15 minutes prior to administering a breath/alcohol test, and a preliminary breath test, in an OWI investigation. The new DataMaster DMT has a count-down screen to help the officers make sure the observation period is followed.
To help facilitate an OWI investigation and ensure greater accuracy in police reports, the DMT has a portable laser printer and a card-reader for driver’s licenses. The DataMaster DMT is much lighter and smaller than previous units.
The DMT captures and saves a digital profile of the breath sample and supposedly can interpret accurately whether a breath sample is intentionally being manipulated or if there is a good faith sample and the machine is not able to determine the breath/alcohol sample. In other words, there should be less technical refusal reports in those situations where a suspect is blowing into the machine in good faith but is simply unable to produce an adequate breath sample.
FALSE POSITIVE READINGS
Body chemistry is one factor that can lead to false positives. People with diabetes, acid reflux disease, or some cancers can fail DataMaster tests even if their bloodstreams are perfectly free of alcohol. Diabetics, for example, have extraordinarily high levels of acetone, a substance that the DataMaster can mistake for ethyl alcohol.
Police recognize that regurgitation can render unreliable the results of a Breathalyzer. This is the reason that Michigan officers are supposed to observe the subject of a breath test for 15 minutes before its administration. Regurgitation includes any instance of fluids or gases that rise through the esophagus.
BLOOD TESTS ARE MORE ACCURATE BUT OFTEN LEAD TO HIGHER RESULTS
The DataMaster is less accurate than a blood test. Whereas a blood test actually measures blood alcohol concentration (BAC), the DataMaster merely estimates it. In recognition of this fact.
What the DataMaster attempts to measure is the presence of chemicals found in alcohol and then use that measurement to determine an accurate blood/alcohol level. But the machine often measures chemicals with molecular structures similar to those found in alcohol. According to studies, over 100 compounds can be found in the human breath at any one time, and 70 to 80 percent of them contain a methyl group structure and will be incorrectly detected as ethyl alcohol.
Mr. Loren M. Dickstein
Lewis & Dickstein, P.L.L.C.
2000 Town Center, Ste. 2350
Southfield, MI 48075