In 1954, Dr. Robert Borkenstein, an Indiana University professor and former captain with the Indiana state police invented the first breathalyzer device to measure a subject's blood alcohol content. Borkenstein's device worked by using photometry, the measurement of a substance's reaction to light, and chemical oxidation, the measurement of oxygen's reaction to other chemicals, to determine the presence of alcohol in the subject's bloodstream. Modern breathalyzer devices have improved upon Borkenstein's design by using infrared spectrometry, a science which more precisely identifies the presence of alcohol in the subject's blood. One major advantage of Borkenstein's invention was that it was smaller and easier to operate than the earlier devices used to measure a subject's blood alcohol concentration, thus making it better-suited for officers to administer roadside.
With the mass production of this device many states started to pass per se impaired DUI laws. Under a per se law, a driver is presumed to be intoxicated when his blood alcohol concentration is higher than a certain level regardless of how impaired he seems to be or how he performs on his roadside tests. Because the modern breathalyzer device provided a numerical value to represent the driver's impairment it became easier for law enforcement to measure a driver's level of intoxication. Also in the 1950s and 1960s, research began to show how a person's driving ability could become significantly impaired at a level of as low as .04 percent BAC. These developments in the scientific community led to all 50 states passing per se intoxication laws.
Modern breath tests for alcohol are generally divided into two categories: preliminary breath tests and evidentiary breath tests. A preliminary breath test is usually the device a police officer will ask a driver to blow into after he has been stopped. A high reading on a preliminary breath test gives the officer a reason to arrest the driver, but the result is generally not admissible in court. An evidentiary breath test is usually given to the driver once he has been taken to the police station. These tests are considered more reliable and are generally admissible in court. Despite the scientific developments in breath tests, these tests are still far from perfect. Modern breath tests can give improper readings for a number of reasons, such as if they have not been calibrated properly for changing temperatures or if the subject has an irregular breathing pattern.
With the mass production of this device many states started to pass per se impaired DUI laws. Under a per se law, a driver is presumed to be intoxicated when his blood alcohol concentration is higher than a certain level regardless of how impaired he seems to be or how he performs on his roadside tests. Because the modern breathalyzer device provided a numerical value to represent the driver's impairment it became easier for law enforcement to measure a driver's level of intoxication. Also in the 1950s and 1960s, research began to show how a person's driving ability could become significantly impaired at a level of as low as .04 percent BAC. These developments in the scientific community led to all 50 states passing per se intoxication laws.
Modern breath tests for alcohol are generally divided into two categories: preliminary breath tests and evidentiary breath tests. A preliminary breath test is usually the device a police officer will ask a driver to blow into after he has been stopped. A high reading on a preliminary breath test gives the officer a reason to arrest the driver, but the result is generally not admissible in court. An evidentiary breath test is usually given to the driver once he has been taken to the police station. These tests are considered more reliable and are generally admissible in court. Despite the scientific developments in breath tests, these tests are still far from perfect. Modern breath tests can give improper readings for a number of reasons, such as if they have not been calibrated properly for changing temperatures or if the subject has an irregular breathing pattern.
