Police sirens

What Is an Intoxilyzer?

Oklahoma residents who are pulled over and suspected of being under the influence of alcohol may be required to give a breath sample. Police may use a device called an Intoxilyzer to obtain and analyze this sample. It will detect the level of ethanol in a person's breath using a process called infrared spectroscopy, which analyzes the molecules based on how they interact with light.

The sample is processed through the device in four steps. The first step involves the lamp inside of the device shooting a beam of light in multiple wavelengths. After the light beam is created, it is sent to a chamber and focused by a lens into a spinning wheel that acts as a filter. The light then passes through the filter and creates an electrical pulse inside of a photocell.

These pulses are then converted into a number that represents the individual's blood alcohol content. Police will use a breath test because they believe it is the most efficient and practical way to determine a driver's blood alcohol content at the time that he or she is detained. In the past, blood samples would be taken in the field or urine tests would be used to determine a driver'a BAC. However, these tests proved to be ineffective or unreliable compared to breath testing.

Drivers who are charged with impaired driving may wish to consult with a criminal defense attorney who can fashion a strategy to help a client avoid penalties such as a fine, a license revocation and possible jail time. It often can be argued that the results of a breath test are inaccurate or were handled improperly, resulting in charges being reduced or dropped.