Intoxilyzer 5000

Texas has approved multiple devices for the purpose of breath testing alleged offenders suspected of driving while intoxicated (DWI), but the Intoxilyzer 5000 remains perhaps one of the most problematic instruments that remain in use in Denton County and many other locations all over the Lone Star State. Title 37 Texas Administrative Code § 19.2 establishes that the Office of the Scientific Director, Breath Alcohol Testing Program, and Texas Department of Public Safety (DPS) must approve and certify all breath alcohol testing instruments to be used for evidential purposes, and to be approved, every instrument must meet the criteria as detailed in the subsection:

  • Expired breath specimens must be analyzed.
  • The instrument must incorporate a reference system, the result of which must agree within plus or minus 0.01g/210L of the nominal value or such limits as set by the scientific director.
  • The specificity of the procedure must be adequate and appropriate for the analyses of breath specimens for the determination of alcohol concentration for law enforcement.
  • Any other tests deemed necessary by the scientific director to correctly and adequately evaluate the instrument to give correct results in routine breath alcohol testing and be practical and reliable for law enforcement purposes.

Police officers claim that the Intoxilyzer 5000 EN shows only the result of the breath tested and the breath comes only from deep lung air. Many scientists, however, say that the Intoxilyzer can misread other commonly found substances in human breath and erroneously cause the device to read high.

Intoxilyzer 5000 Defense Lawyer in Denton, Frisco, Lewisville, Flower Mound, TX

If you were arrested for DWI following an Intoxilyzer 5000 test, you deserve to know if your test was actually accurate. It may be possible that the device estimated your blood alcohol concentration (BAC) was much higher than it actually was.

The Law Offices of Richard C. McConathy aggressively defends people accused of DWI in Denton and many surrounding areas, such as Argyle, Aubrey, Carrollton, Flower Mound, Frisco, Justin, Krum, Lake Dallas, Lewisville, Little Elm, Pilot Point, Ponder, Roanoke, Sanger, and The Colony. You can call our firm at (940) 222-8004 or contact us online to schedule a consultation so we can begin reviewing your case.

How the Intoxilyzer 5000 Works

Molecules absorb infrared energy at specific wavelengths depending on the elements that comprise them and their structure. Detailed absorption spectra will often be used to determine a kind of chemical. 

Absorption at a certain wavelength of infrared energy is used to measure the concentration of a chemical per the Infrared Absorption Principle. This is the method used by the Intoxilyzer 5000 to measure alcohol concentration in breath samples. 

The optical bench of the Intoxilyzer 5000EN involves a Quartz iodide lamp, a lens, the sample chamber, a second lens, the filter wheel and detector. A filter wheel has five filters; one for reference, one for measuring alcohol and three for detecting interferents, meaning chemicals other than alcohol. 

Infrared light hitting the detector is converted to an electrical signal. Each filter produces a separate signal. 

The instrument electronics tracks each signal as a separate “channel”. A drop in the electric signal from the detector is proportional to an alcohol concentration.

Initially, the instrument establishes a zero reference point for each channel by measuring the detector output when the sample chamber is filled with room air. During a breath test or simulator analysis (Cal Check), as the amount of alcohol vapor in the chamber rises, the amount of infrared light reaching the detector falls. The test mode sequence for the Kentucky Model Intoxilyzer 5000EN is A-C-A-B-A

  • A – Air Blank
  • C- Simulator Analysis (Cal Check)
  • A – Air Blank
  • B –Breath Sample
  • A – Air Blank. 

To ensure a proper test, a variety of checks are made on the air sample, the simulator sample, the breath sample, the reference channel, and the interferent channels. If any of these checks do not meet specifications, the test is stopped.

The external instrument parts on an Intoxilyzer 5000 include a breath tube that is a heated reinforced plastic tube through which the subject blows into the sample chamber, a mouthpiece that is a disposable clear plastic trap which fits into the end of the breath tube, accepts the subject’s breath, and prevents unwanted substances from entering the instrument, a digital display that is a 15-character alphanumeric readout that relates which operation the instrument is performing, alerts the operator to required actions, and expresses BAC results in grams per 210 liters of breath, a start test button that is a push button switch (green) used to initiate a test, invalidate a test, attempt to correct an instrument error; or activate instrument from the stand-by mode, a power switch that is a push button switch (red) used to apply ac power to the instrument, a red diode light that is indicates the instrument is on and electrical power is being provided, a simulator vapor port that is an adapter through which alcohol vapor passes from an attached alcohol wet bath simulator to the instrument’s sample chamber, an evidence card that is a formatted, multi-copy card that provides a printed record of the administered test, a power cord that is an 8 ft. cord that supplies power to the instrument, a serial number located on the back of the instrument, and a modem phone jack that is located on the rear of the instrument to insert a phone line and allows the technician to contact the instrument by telephone.

Problems with the Intoxilyzer 5000 in Texas

Neither the manufacturer nor the DPS allows anyone other than law enforcement personnel to test either the accuracy of an Intoxilyzer 5000 or its reliability. It is typically understood that for a procedure to be accepted as accurate and reliable, that procedure should be open and available for the scientific community to test and retest.

The slope detector of the Intoxilyzer can be fooled by utilizing a slow, steady blow into the collection tube. In a February 1995 demonstration at a Minnesota Society for Criminal Justice (MSCJ) national DWI seminar, Dr. Richard E. Jensen showed a readout of 0.472 for a subject whose actual BAC level was approximately 0.06 percent and had swished scotch whiskey in his mouth.

During an Intoxilyzer 5000 training program the following year, defense attorneys tested the slope detector again. An Atlanta-area lawyer in one test whose BAC was actually 0.15 had two readings of more than 0.70 on an Intoxilyzer 5000 operating in the two-digit mode.

Furthermore, the air blank portion of the Intoxilyzer 5000 always reads 0.000, regardless of whether an ambient air sample has alcohol or other volatile chemicals in it. At the same MSCJ National DWI seminar in 1995, this was proven by a lawyer who had been moderately drinking and blew into the collection tube. 

The man’s BAC level was approximately 0.06 and the air blank intake port was exposed to a glass of Scotch whiskey during the air blank sample, but during the air blank mode, it read 0.000. The machine reported no type of malfunction or indicate alcohol in the sample chamber.

The machine malfunctions but does not give a false test result without alerting an operator to the issue. Because an ambient air detector caused the baseline to go to “0.000,” a 0.06 reading could be reported as a false negative and thus provided a zero reading.

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Excluding Intoxilyzer 5000 Evidence in Denton Courts

In many DWI cases in the Denton area involving Intoxilyzer 5000 evidence, the goal of your DWI defense attorney should be to exclude breath test results. This is usually accomplished by making one or more specific pretrial motions. 

If a motion to exclude the evidence is granted by the judge or court, the prosecutor cannot mention either the breath test or its results at trial to a jury. DWI tests can be excluded from the evidence that is presented at trial if:

  • The driver submits to the breath test before an arrest
  • Police violated the driver’s right to obtain independent blood, breath, or urine test
  • Police failed to substantially comply with rules or procedures regarding the Intoxilyzer 5000

Some of the possible violations of Intoxilyzer 5000 rules include:

  • Failing to allow the 20-minute observation period before breath testing
  • Giving unauthorized individuals access to the breath-testing device
  • Failing to recognize the aforementioned medical conditions
  • Using tap water instead of distilled
  • Refusing to reveal to attorneys the machine’s code or other information regarding software or hardware flaws.

Denton County Intoxilyzer 5000 Resources 

Texas DPS | Certified Breath Test Instruments — View the full list of breath test instruments approved and certified for breath testing in Texas in compliance with Rule 19.2 of the Texas Breath Alcohol Testing Regulations. You will notice all three of the approved models are Intoxilyer brands, including the Intoxilyer 5000 with Cooled Detector, the Intoxilyer 5000 EN, and the Intoxilyer 9000. The Scientific Director certifies qualified forensic scientists as Technical Supervisors to provide technical, administrative, and supervisory expertise in safeguarding the scientific integrity of the breath alcohol testing program and to ensure the breath alcohol testing program’s acceptability for evidential purposes.

Approved Evidential Breath Measurement Devices — This United States Department of Transportation (DOT) page shows the only devices law enforcement can use to conduct alcohol confirmation tests under 49 Code of Federal Regulations Part 40. Approved evidential breath measurement devices listed here include the Intoxilyzer 200, Intoxilyzer 200D, Intoxilyzer 240, Intoxilyzer 300, Intoxilyzer 400, Intoxilyzer 400PA, Intoxilyzer 500, Intoxilyzer 600, Intoxilyzer 1400, Intoxilyzer 5000, Intoxilyzer 5000 (w/Cal Vapor Re-Circ), Intoxilyzer 5000 (w/3/8² ID Hose option), Intoxilyzer 5000CD, Intoxilyzer 5000CD/FG5, Intoxilyzer 5000EN, Intoxilyzer 5000 (CAL DOJ), Intoxilyzer 5000VA, Intoxilyzer 8000, Intoxilyzer 9000, Intoxilyzer S–D2, and Intoxilyzer S–D5. The DOT states that to conduct a confirmation test, an officer must use an EBT that provides a printed triplicate result (or three consecutive identical copies of a result) of each breath test; assigns a unique number to each completed test, which the BAT and employee can read before each test and which is printed on each copy of the result; prints, on each copy of the result, the manufacturer’s name for the device, its serial number, and the time of the test; distinguish alcohol from acetone at the 0.302 alcohol concentration level; tests an air blank; and performs an external calibration check.

Find A Denton County Defense Attorney for DWI Charges from an Intoxilyzer 5000 Test | Law Offices of Richard C. McConathy

Were you arrested for DWI after an Intoxilyzer 5000 test? It will be important for you to speak to an experienced criminal defense lawyer about what rights you have to challenge those test results.

The Law Offices of Richard C. McConathy will aggressively defend you against DWI charges and fight to get the charges reduced or dismissed. You can call (940) 222-8004 or contact us online to take advantage of a consultation.