Faults and Limitations of Blood-Alcohol Level Testing Devices

To assist with the confusion officers might have with the Verifier/DataMaster’s, Verax has error messages pop-up on the LCD display. This is designed to help officers troubleshoot the error. The Service Guide lists the following as possible error messages. Note that there is no error message to warn an officer that the CPU is malfunctioning, and may not be detecting or reporting the following malfunctions.

• Low Temperature
• High Temperature
• Printer Error
• CRC Error
• Pump Error
• System Will Not Zero

This section of the service guide is followed by the notation that, "It is possible that there may be physical blockages of the IR (infrared) energy along the path from Source to Detector... Such blockage may be due to:

• the presence of simulator solution in the sample chamber when the simulator is hooked up to the instrument incorrectly.
• cracked windows or mirrors.
• failure of the chopper wheel to turn.
• the formation of condensation or fog building up on windows or mirrors due to leakage in the system.
• the presence of any other foreign material in sample chamber.

• there is No Heat in the Breath Tube
• the Blinking Stops But There is No Sample instrument Samples Early, By Itself
• the Blinking Does Not Cease When The Instrument is Blown Into
• the Supervisor Buttons Fail to Work
• the Instrument is Difficult or Impossible to Blow Into
• the Pump Operates Improperly
• there is No Reading on the Display
• the Machine is "Not Calibrated"
• the Printer Runs Non-stop
• the MTR Button Doesn't Function

The Operator's Manual lists additional ways the BAC Verifier/Datamaster can malfunction caused by: an invalid sample (the manual reads "mouth alcohol is being detected, subject is not providing a proper sample, or the instrument is out of adjustment"—it is not clear what invalidates the sample.)

• RFI
• Calibration Error—Fatal Systems Error

The above mentioned problems are only the more common errors with the Verifier/DataMaster. There are so many errors even Verax is struggling to identify all of the problems with their machine. The following quote from their Service Guide confirms this observation: "If your instrument exhibits a symptom that is not identified in this guide, please notify us so that we may update our symptom information library" (emphasis added). They included this because Verax knows there is an entire library of errors, malfunctions, faults, and miscalculations with these machines.

Luckily Verax installed an internal self-checking diagnostic system, run by its computer. In theory this readily available diagnostic check could detect malfunctions in the machine and report them. Unfortunately these checks are performed only periodically and not before each new test. Not to mention the computer could already be corrupted by one of the many errors. If, on the off chance that the computer dodges the countless errors despite the defunct design, and performs a check right before a test, it could notify the officer that the simulator solution is not at 50 degrees centigrade and safeguard a DUI suspect from the repercussions of a false positive.

Breath testing machines that use infrared absorption suffer from even more problems. They are covered in further detail in the links below:

Infrared Analyzer
The basic design of an infrared analyzing machine designed to measure blood-alcohol content.

The Science of Breath Testing
A recognized Professor of Pharmacology holds a scholarly discussion of the physiological basis for breath alcohol testing.

Breath Testing Machine
For information on breath testing and breathalyzers.

The Drunk Driving Law Center
Huge website with discussions, links, and information relevant to blood alcohol levels, blood, and breath alcohol analysis.

Alcohol and the Human Body
A discussion on how ethanol effects of the physiology of a human.

California DUI Laws San Francisco Bay Area Courts, Prosecutors and Police Finding a Good DUI Attorney in the Bay Area Drunk Driving Punishment Blood-Alcohol Levels Standard Field Sobriety Tests Breathalyzers The Eye Test Blood-Alcohol Tests Chain of Custody Blood Hematocrit License Suspensions DUI Search Help Home

Copyright 2000 - 2008

Site Map | Legal Disclaimer

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.