Like the Intoxilyzer 5000 and Intoximeter 3000 commonly used throughout California, the Datamaster operates on the principle of infrared analysis. And as with those devices, the machine is subject to all of the flaws of infrared analysis-nonspecificity.
The designers of the Datamaster, opted for the faster and cheaper infrared method of analysis, hoping to minimize the problem of lack of specificity by utilizing two wavelengths. The microcomputer was integrated to control sequencing, calibration and self-checking, making it easier to use and less susceptible to operator error. Additionally, the software can be custom-designed to meet the requirements of a given jurisdiction or the specific needs of an agency.
The detachable breath tube contains a sealed wire-wrapped antenna for the purposes of detecting radio frequency interference. Further, the manufacturer offers two options:
1. An "external alcohol simulator standard pump outlet" for purposes of testing the accuracy of the machine.
2. A sample preservation system -- a mechanism for inserting a vial to capture and preserve a second breath sample for subsequent analysis, either for double-checking or for defense testing.
Subsequent to production of the BAC Verifier, Verax Systems designed the BAC Verifier DataMaster -- primarily for use in Washington State. The principle of operation for the DataMaster is the same as for its parent machine; the differences lie in the changes made to comply with the state's bidding requirements. The case of the Datamaster is metal, for example, while the original machine is plastic impregnated with metal; this was done, in theory, to reduce the chances of radio frequency interference. Other changes include a different printer to provide multiple copies of the evidence ticket; a different layout of the printed circuit boards to make the machine easier to maintain and repair; a new central processing unit (CPU) to inhibit the electrical interference previously noticed in the poorly designed circuitry of the original Verifier; significantly different data collection and storage software -- most notably, changes in the formula used to calculate the presence of acetone in a breath sample and in the previously defective "erasable programmable read only memory" (EPROM) used to calculate BAC; and changed breath-tube mounting.
Two interesting observations can be made about the Datamaster. First, the changes required by Washington State clearly indicate rather significant deficiencies in the existing Verifier used in other parts of the country. Second, the Datamaster itself has encountered problems: Eight of the first machines received had to be returned because they failed to meet specifications; twenty-five have had to be repaired because of a variety of problems. Common problems included inaccurate readings because of meter valve instability, failure to detect the presence of acetaldehyde and false readings caused by infrared lamp instability.
The Verifier/Datamaster has a number of components that are very sensitive to temperature change..
1. The simulator solution, as with any breath machine, must be kept at 34 degrees centigrade, plus or minus .02; a decrease of one degree will cause a 6.8 percent decrease in the amount of alcohol, resulting in a falsely higher BAC reading for tested breath samples. A thermometer attached to the simulator is supposed to be checked by the operator.
2. The sample chamber must be heated to exactly 50 degrees; this is supposedly monitored by the machine's computer.
3. The detector must be cooled almost to freezing; this is also theoretically monitored by the computer.
4. The breath tube must be heated to 50 degrees. If not properly heated, condensation can form in the tube; this can capture alcohol during a test, which will be picked up by later breath samples. Despite the need for a 50 degree temperature, the Operator's Manual tells the operator only to "check that the mouth piece is warm to the touch."
It is also of interest that the Verifier/Datamaster's Service Guide lists the following possible error messages on the LCD display. Note, incidentally, that there is nothing to indicate that the computer is malfunctioning, such as by not detecting and reporting the following malfunctions.
• Temperature Low
• Temperature High
• Printer Error
• CRC Error
• Pump Error
• System Won't Zero
This last entry 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..... Possible causes of blockage:
• Simulator solution in sample chamber. This can occur if the simulator is hooked up to the instrument incorrectly.
• Cracked windows or mirrors.
• Chopper wheel not turning.
• Condensation or fog building up on windows or mirrors due to leakage in the system.
• Any other foreign material in sample chamber.
The Service Guide then continues with a list of what it terms "functional errors"; that is, malfunctions for which there are no error messages to alert the operator:
• No Breath Tube Heat
• Blinking Stops, But No Sample
• Instrument Samples Early, By Itself
• Blinking Does Not Stop When Instrument is Blown Into
• Supervisor Buttons Don't Function
• Difficult or Impossible to Blow Into Instrument
• Improper Operation of Pump
• No Display
• "Not Calibrated"
• Printer Runs Continuously
• MTR Button Doesn't Function
The Operator's Manual adds a few more ways the BAC Verifier/Datamaster can malfunction:
• Invalid Sample (the manual reads "mouth alcohol is being detected, subject is not providing a proper sample, or the instrument is out of adjustment"--but does not indicate which )
• Calibration Error--Fatal Systems Error
These, the manuals stress, are only the more common sources of error possible with the Verifier/Datamaster. The Service Guide adds the following interesting comment: "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). This for two reasons:
1. There is an entire library of things that can go wrong with this machine!
2. The manufacturers are not even aware of some things that can go wrong: They are soliciting information about newly discovered defects for their presumably ever-growing library. What malfunction will be discovered next!
It is also interesting to note that the Verifier/Datamaster has an internal self-checking diagnostic system, run by its computer. Of course, garbage in equals garbage out, but in theory such a readily available diagnostic check might detect malfunctions in the machine. Yet these checks are performed only periodically and not before each test. Despite the fact that such a check would detect, for example, whether the critical temperature of the sample chamber is 50 degrees, such a check is almost never done immediately before or after a DUI suspect is tested.
There are more problems that are associated with any breath testing machine that use infrared absorption. Call us to find out more about problems associated with Breath testing.