Over the past several months, the State has been replacing its old breath alcohol testing machines, the Intoxilizer 5000EN, with a newer model, the Intoxilizer 8000.  Both the Intoxilizer 8000 and 5000EN operate on the principle of infrared spectroscopy, measuring the amount of infrared light absorbed in the sample chamber as it passes through a sample of deep lung air supplied by the test subject.   Infrared light is absorbed at measured wavelengths by the carbon-hydrogen bond in alcohol molecules.   The Intoxilizer’s computer calculates a breath alcohol level based on the detected decrease in infrared light as it travels from the light source at one end of the sample chamber to the detectors at the other end.  At this level of generality, the operation of the Intoxilizer 5000EN and the operation of the Intoxilizer 8000 are essentially similar.

Both the Intoxilizer 5000EN and the Intoxlizer 8000 are designed to flag problems with the machine itself and with the breath testing process by producing certain error messages.   Several changes have been made in those error messages, and/or in the descriptions of those error messages in the Intoxilizer Operation and Certification Student Manual, between the manual for the Intoxilizer 5000EN and the manual for the Intoxilizer 8000.


1. Insufficient Sample, has become Deficient Sample.  The Intoxilizer 5000EN reports a person’s failure to provide an adequate breath sample within 3 minutes by printing a * next to the subject test and the words “Insufficient Sample” on the printout.  The Intoxilizer 8000 instead prints DEF* next to the subject test and the message “*Deficient Sample” on the bottom of the printout.  This change was probably made to reduce the confusion common among Intoxilizer operators between the Intoxilizer 5000 EN’s “Invalid Sample XXX” error message (discussed immediately below) and its “Insufficient Sample” error message.

 2. Invalid Sample XXX.  When the Intoxilizer 5000EN was first placed in service in Maine, it was accompanied by an operator’s manual produced by the manufacturer, CMI, Inc.  In that manual, CMI explained that the Invalid Sample XXX error message meant the machine had detected residual mouth alcohol in the subject’s breath.  The manual went on to explain that, because residual mouth alcohol is eliminated within 15 minutes by normal body processes, the Intoxilizer operator must abort the testing process and start another test after observing the test subject for a new 15-minute period.

In 2000, CMI issued a revised operator’s manual.  In that manual, the manufacturer changed its instructions for operators encountering an Invalid Sample XXX message.   In the revised manual, the operator was informed that the function was originally designed to detect mouth alcohol, but that there could be other causes.  CMI’s revised manual explained that any breath sample that met the profile for an invalid sample would cause the error message to occur and that the message could be caused by puffing into the breath tube or moving the mouthpiece during a test.   The manual instructed that an operator who suspected mouth alcohol was to observe the test subject for another 15 minutes before beginning a new test.

After the year 2000 revision to the CMI operator’s manual, the Maine Criminal Justice Academy picked up on CMI’s revision and expanded it.  The Criminal Justice Academy, in its Intoxilizer 5000-EN Operation and Certification Manual, began instructing Intoxilizer operators that, although the test was originally designed to detect residual mouth alcohol, the Invalid Sample XXX message can occur any time a breath sample meets the profile for an invalid sample. Without explaining what the profile for an invalid sample is, the manual stated in bold and underlined text that the error message might not result from residual mouth alcohol but might be caused by puffing into the Intxolizer, sucking back, or moving the mouthpiece during a test.   Again, sucking back on the breath tube was not acknowledged as a potential cause of the Invalid Sample XXX message in either the revised or unrevised operator’s manual produced by CMI.  The Criminal Justice Academy’s manual did not cite any authority for its claim.   The Academy’s manual did, however, instruct operators that if they suspect residual mouth alcohol they must terminate the test and observe a new 15-minute observation period before conducting a new test.  The manual also instructed that if puffing, sucking back or moving the mouthpiece was suspected the officer should articulate those observations in the police report and either: (1) warn the suspect that continuing the conduct will result in a refusal determination, before attempting to proceed with the test; (2) provide that same warning before starting a new observation period and administering a new test; or (3) end the test and mark the subject as a refusal due to non-cooperation.

For Maine’s version of the Intoxilizer 8000, CMI did not produce an operator’s manual.  The only existing operator’s manual for Maine’s Intoxilizer 8000 is the one produced by the Criminal Justice Academy.   The Academy’s manual for the Intoxilzer 8000 maintains that the Invalid Sample XXX error message may be caused by sucking back as well as by puffing or moving the mouthpiece.  Unlike the Intoxilizer 5000EN operator’s manual, the 8000 manual does not mention that the test was originally designed for detection of residual mouth alcohol.  Instead, it states that the Intoxililzer is designed to flag breath samples that “meet [the] criteria” of sucking back, puffing or moving the mouthpiece.  Because CMI did not produce a manual for Maine’s version of the 8000, there is no longer a readily available authoritative source to rebut the Criminal Justice Academy’s manual as to what the Invalid Sample XXX message was designed to flag or what, other than residual mouth alcohol, might cause it to occur.   Officers are still instructed that when residual mouth alcohol is suspected they are to terminate the test and begin a new observation period.  They are also still given three options for what they should do if they suspect that the error message is caused by sucking back, puffing or moving the mouthpiece:  (1) warn the test subject that continued non-cooperating will result in a test refusal determination before attempting to continue with the test; (2) provide these same warnings to the test subject before beginning a new observation period and then starting a new test; or (3) end the test and mark the test subject as a refusal for non-cooperation.

3. INHIBITED RFI has become RFI DETECT:  The error message still indicates that radio frequency interference has been detected, causing the test to abort.

4. INTERFERENT or INTERF DETECTED, SUBTRACTED has become INTERFERENT DETECTED.  This is an indication that the Intoxilizer 8000 has detected an interfering substance that absorbs infrared light at the same measured wavelength as alcohol.   Unlike with the Intoxilizer 5000EN, no claim is made that the 8000 is able to accurately subtract acetone from a test result. The operator is instructed to give the test subject another type of test if this error message occurs.

5. CAL CHECK OUT OF TOLERANCE.  This error message is new.  It indicates that one of the internal standards has been measured outside the allowable range of + 0.005 of its target value.  The 8000 prints the message INVALID TEST, CAL CHECK OUT OF TOLERANCE.  Operators are allowed to proceed with another test but are instructed to contact the State Lab for service if this error occurs repeatedly.

6. Other error messages remain the same from the Intoxilizer 5000EN to the 8000.

The Intoxilizer 8000 Operation and Certification Student Manual may be viewed here: