The Intoxilyzer 5000 costs about $7,500.
There are several models of the Intoxilyzer 5000 in use in Arizona
including the model 64, 66, 68 and 68-EN. Many of these earlier
models have been in service for 15 or more years.
Intoxilyzer 5000 is simply a computer based on very old technology.
The brains of this outfit is a Z-80 microprocessor which was introduced
almost 30 years ago in 1975. The Z-80 microprocessor was the basis
for some of the very first home computers in the early 1980's.
Remember the "Radio Shack" TRS-80.
Intoxilyzer 5000 works on the theory of infrared absorption. The machine has a light bulb positioned at one end
of a breath capture cylinder. There are filter wheels at the other end of the cylinder
and on the other side of these filter wheels is a light receiver.
A person suspected of or under arrest for DUI will
blow into a breath tube which leads to a breath chamber cylinder. The
machine shines a light through this cylinder and the filter wheels will be
spinning on the other end of the breath tube chamber. The infrared
light causes the alcohol molecules to "vibrate" or "absorb" light at a
particular frequency. The filter wheels are designed to filter out
The amount of the breath sample and any reading of
alcohol are very minute. The machine must make a multiplication conversion
to an amount great enough for us to understand. The difference in light
emitted and received is computed through a computer program in the machine
to come up a value that can be compared to a .08. The conversion the
machine makes on the differences in light would be the equivalent of
taking the paper towel tube and increasing its size to that of a 55 gallon
drum! Any error would then be exaggerated by that amount.
HOW RELIABLE IS THE BREATH TEST?
There is much debate on the Intoxilyzer 5000.
Proponents of it state that the machine will only read light absorbed by
alcohol, while opponents state the machine often misreads as alcohol other
commonly found substances in the breath, thus giving an inaccurate high
only requires that the Intoxilyzer 5000 perform within a plus or minus 10%
accuracy rate. This means that a 20% variance in "ok for government work".
When the machine is periodically checked for proper function and accuracy
and known value of alcohol solution -- 0.080 -- is used to test the
machine, if the results are within 0.072 and 0.088 the machine is deemed
to be working properly.
example is if you are stopped and arrested for DUI and take a breath test,
and you blow a 0.080, when your actual alcohol content is something less,
you still face the additional charge of driving with a .08 or higher. Very
The manufacturer does not warrant the
for any particular purpose. The machine is not warranted for accurate
and reliable breath testing.
The Intoxilyzer also assumes that everyone tested
will have a blood/breath ration of 2100/1 (i.e. 2100 parts of alcohol in
the breath for every 1 part of alcohol in the blood). If a person has a
higher blood/breath ratio (i.e. 2400/1) the test will not be adversely
affected by this assumption. However a person with a lower blood/breath
ratio will be adversely affected because the Intoxilyzer will erroneously
read too high, thus a person who should test at .05 or .06 could actually
test well above a .08 Additionally, scientists have documented
people with blood/breath ratios as low as 1100/1.
A person with a fever will have a higher breath test
reading than an identical person without a fever. Therefore, the
temperature of your body can affect what the Intoxilyzer reads, and your
body temperature has nothing to do with the amount of alcohol you may have
or have not consumed.
REGARDING THE INTOXILYZER 5000