Breathalyzer Faults and Limitations

The term “breathalyzers” applies to a variety of breath-testing systems employed in resolving drunk driving cases in San Francisco and other parts of California. The “BAC DataMaster” is a commonly used breathalyzer. It is susceptible to the flaws of infrared analysis, as many of the other breathalyzers used in DUI investigations since they also use infrared analysis.

The creators of the Datamaster were looking to make the machine less complicated and not so prone to operator error. In order to do this, the microcomputer was designed to control sequencing, calibration, and self-checking. In an effort to fix the flaws of infrared analysis-nonspecificity, the creators used a quicker and less expensive infrared method of analysis by utilizing two wavelengths. An option to custom-design the software to match the given jurisdiction or particular requirements of an agency was also included.

In order to detect radio frequency disturbance, the removable breath tube holds a sealed wire-wrapped antenna. The creators also provide a few choices:

1. Sample preservation system: The machine has the ability to capture and hold a second breath sample. This is either for affirmation of the first breath sample result, or for defense testing.
2. “External alcohol simulator standard pump outlet” – Created with the intention of assessing the accuracy of the machine.

Verax systems created the BAC Verifier DataMaster soon after the BAC Verifier was produced. Changes made to the model were made to conform to the states bidding laws. Essentially for use in Washington state, the actual purpose for the BAC Verifier Datamaster is the same as the previous machine. Changes to the updated Verifier include:

1. In order to reduce radio interference, the updated Verifier has a metal casing rather than the original plastic used.
2. A new printer that allows for more than one copy of the ticket to be printed.
3. A new CPU (central processing unit) in an effort to reduce electrical interference that the previous model experienced.
4. Remarkably different data collection and storage software.
1. The best change is the equation used to find the amount of acetone present in a breath sample.
2. This also corrects the “erasable programmable read only memory” (EPROM) that was used to compute the BAC, which was defective in the earlier model
5. A new mounting for the breath-tube

The Datamaster has continued to see problems since its production, though. An interesting thing to note, the alterations required by Washington State suggested exceptional deficiencies in the previous Verifier. With the problems with the Datamaster, the first eight models were returned due to not meeting the new guidelines. After that, twenty-five have needed to be serviced with a range of issues. These problems include meter valve instability that cause imprecise results, inability to detect acetaldehyde, and inaccurate readings due to infrared lamp instability.

Both models have numerous parts susceptible to alterations in temperature:

1. At risk of altering the BAC reading, the simulator solution must be kept at 34 degrees centigrade (with a grace area of plus or minus .02). If the temperature decreases one degree, there will be a 6.8% decrease in the level of alcohol. This will create an incorrect higher BAC reading with the breath samples. It is the operator’s responsibility to check the thermometer attached to the simulator.
2. Hypothetically controlled by the computer, the detector has to be chilled to nearly freezing.
3. Also detected by the computer, the sample chamber has to be heated to exactly 50 degrees.
4. The breath tube also requires a temperature of fifty degrees. The Operator’s Manual simply tells the operator to “check that the mouth piece is warm to the touch.” However, if the tube is not heated to the exact temperature, condensation can catch inside which will catch alcohol. Not only will this alter the results for the first test, the alcohol will be caught by the meter on later tests also changing that result.

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San Francisco DUI Laws and Lawyers is an informational resource for those facing criminal DUI charges in San Francisco, San Mateo County, Marin County, Napa County, Sonoma County, Alameda County and Contra Costa County. This is also a movement formed to resist the increasing pressures by radical groups on courts, prosecutors and legislators for more excessively stringent DUI laws, increasingly harsh sentences, more circumvention of our Constitutional protections, and eventually a return to the days of Prohibition. The National Motorists Association website sheds light on important DUI-DWI issues such as the constitutionality of roadblocks, admissibility of questionable breath tests, officer-administered license suspensions, and inappropriate penalties in drunk driving cases.