How is breath testing done?
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Oklahoma uses a machine called the Intoxilyzer 5000-D, which is commonly called the “breathalyzer”. (I call it the Intoxiliar because of its inaccuracies)
- The Intoxilyzer 5000-D costs about $7,500. Some models have been in service for 15 or more years.
- The Intoxilyzer 5000-D is simply a computer based on very old technology. The brain of this thing is a Z-80 microprocessor, which was introduced in 1975, over 30 years ago. Remember the “Radio Shack” TRS-80? Its processor was the Z-80.
- The machine works on the theory of Infrared Spectrosphopy, which is the absorption of infrared light. There is a light bulb at one end of the breath cylinder and at the other end is a filter wheel with 3 filters. As you blow into the tube, the theory is that alcohol will absorb the light rays and not show up on the filter wheel.
- The amount of Breath actually measured is very small (only 81 cc.) and must be converted to a number we will understand. The conversion the machine makes would be similar to taking a paper towel tube and increasing it to the size of a 55-gallon drum. Any error in the testing will be exaggerated by that amount.
