Do you want to breathe a low test result? Or make sure it does not cause false reading? It's not that hard, says a San Diego DUI lawyer and attorney lawyer: simply direct your breathing.
The simple fact is that these respirators, which determine guilt or innocence in DUI cases, are not exactly the reliable tools that law enforcement believes in us. There are dozens of factors that can cause false results. An example of such unreliability is that the results vary depending on the person's breathing pattern. This has been confirmed by a number of scientific studies
For example, one group of people consumed moderate amounts of alcohol and measured their blood alcohol levels by gas chromatographic analysis of their respiration. The ventilation techniques were then changed. The results showed that breathing for 30 seconds before exhalation increased blood alcohol levels by 15.7%. Hyperventilation for 20 seconds immediately before ventilation reduced the level by 10.6%. The mouth was blocked for five minutes and the shallow nose growth was increased by 7.3% in the blood alcohol level and the slow 20-second exhalation test increased by 2%. ("Respiratory techniques may influence the results of respiratory-alcohol analysis", 22 (4) Medicine and Law 275.)
Dr. Michael Hlastala, Professor of Physiology, Biophysics and Medicine at the University of Washington, said:
"The most noticed error in respiratory testing is the breathing pattern of alcohol … The concentration of alcohol changes significantly during respiration … First part of breathing after dropping the dead space, it has a much lower alcohol concentration than the equivalent BAC (blood alcohol concentration), while in the last part of the breath the alcohol consumption is much higher than the equivalent BAC. The last part of the breath can rise over 50% above the alcohol level … Thus the 0.14% respirator from the last part of the breath may indicate that the blood level is only 0.09%. "9 (6) Champion 16 (1985).
Many policemen know this. They also know that if the machine contradicts their conviction that the arrested person is disgusting, they will not look good. So when they tell the arrested person that he blows into the mouth of the machine, they shout: "breathe, harder," as Professor Hlastala has found, that ensures that the breath taken by the machine is located near the alveolar bags near the bottom of the lungs, The higher the alcohol concentration, the machine gives a larger but inaccurate reading.