The day is here for San Diego County's government
approved roadside DUI evidentiary breath test machines.
With many limitations, including but not limited to those
limitations mentioned below, San Diego Police Department's
Model 8000 is one example of such a government attempt at
an approved roadside machine.
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The Intoxilyzer 8000 is used in San Diego PD DUI
cases (http://www.sandiego.gov/police/).
Intoxilyzer 8000 operates on a principle known
as the "Lambert-Beer Law," which states
that the amount of infrared light absorbed by your
breath is proportional to the amount of alcohol
in the sample. Think of it like the way in which
fog will block your car's headlights on a damp night.
In short, the more alcohol there is, the less infrared
light that gets through the chamber to the detector.
The Intoxilyzer theoretically detects alcohol by
IR / infrared spectroscopy. |
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The Intoxilyzer has a lamp which generates
a broadband infrared beam. The broadband infrared beam passes
through the sample compartment. The beam is centered by
a lens onto a revolving filter wheel. The filter wheel has
narrow band filters theoretically made to read the wavelengths
of the bonds in ethanol. Light passes through each filter.
That light is identified by the photocell. The light is
then converted to an electrical pulse. The electrical pulse
is sent to the microprocessor which purportedly reads the
pulse and then estimates one's BrAC. This estimate is based
on the absorption of the infrared light.
Valuing an estimate seems somewhat inherently unreliable
and/or inaccurate, particularly in light of modern science.
Intoxilyzers reasonably appear outdated in light of new
breath testing machines available for San Diego DUI law
enforcement to purchase.
Another concern with some of the present breath testing
machines is that they can read in the 3.x-3.8 micron range.
This is where the Methyl (CH3) group provides a strong absorption.
This is also where a lot of hydrocarbons absorb infrared
light. Methanol and Isopropanol, and a few other chemical
substances such as menthol and D-Limonene, and others, provide
highly enriched false positives on breath test machines.
These are a few of the many interferents evidenced in San
Diego DUI courts.
The infrared could be blasting through exhaled breath molecules
in a San Diego DUI breath test chamber, or the finger of
the San Diego breath test arrestee. The critical question,
regardless, is where the infrared detector is reading. Any
machine will have to theoretically have sufficient points
to distinguish ethanol from all other potential interferents.
Specificity and calibration are a couple of the central
San Diego DUI issues. Check to see if appropriate reviews
are performed. If the machine is specific to ethanol alone,
then there should be no problem. But if they pick the wrong
points to read, or too few, or ones with potential interferents,
then this will just be another problem. And that is often
the case. Fat concentrations may also be an issue. There
are many possible San Diego DUI breath testing issues and
problems.ever, there are other compounds, called "interferents,"
which can also block the infrared. And the Intoxilyzer cannot
reliably tell them all apart!! !!
Draeger Corporation has reportedly developed an even better
machine. But San Diego County does not have a Draeger machine.
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Draeger Alcotest 7110
The Draeger Alcotest 7110 is used for San Bernardino
and Riverside County DUI cases.
More information about the Draeger
Alcotest 7110:
http://www.southern-california-dui-defense.com/draeger.html
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Draeger Alcotest 7410
The Draeger Alcotest 7410 is used for Orange County
DUI cases |
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Draeger and Intoximeter purportedly adopted
a newer approach to DUI breath testing evidentiary units.
Latest instruments theoretically utilize both an infrared
detector and a fuel cell sensor combined in one intricate
unit. Both values have to be congruent before the DUI breath
test results are displayed. They further attempt to use
infrared measurements in both the 3 & 9 micron ranges,
to purportedly isolate the fingerprint of ethanol.
The temperature sensor built into the Draeger instruments
may potentially be prudent, given the possibility the lung
temperature may adversely affect true BAC (Blood Alcohol
Concentration) readings. Improvements by Draeger can only
validate the testing process, and will hopefully be refined
in future machines.
There's the possibility of creating a machine that would
utilize an infrared penetration of energy through the skin
of the test subject. The blood alcohol reading would be
obtained from the mixed arterial, capillary and venous blood
in the extremity. One would have to determine an appropriate
frequency to use, one that was specific to ethanol without
providing a false-positive reading from interference with
blood, oxygen, carbon dioxide, skin, bone, etc.
A possible advantage would be its potential ability to obtain
a true BAC without converting from a BrAC (Breath Alcohol
Concentration) reading. There would theoretically be no
delays in use, extrapolation of a BAC from a BrAC using
a partition ratio, no invasiveness in the testing procedure,
and little inconvenience. Interferents could possibly be
better managed by the prospective use of a number of frequencies,
theoretically one each for the commonly misread substances.
New, Better Machine
Now, a machine developed by TruTouch Technologies of Albuquerque,
N.M., and named one of the top inventions of 2006 by Time
magazine, uses near-infrared light to detect alcohol in
a person’s system. It reportedly distinguishes differences
in skin to match up registered users and prevent fraudulent
readings. Here's how the simple technology works, according
to TruTouch's amazing Jim McNally, Ph.D.: Body tissue with
alcohol in it absorbs more light than normal tissue without
alcohol. The machine shines light against the skin of the
forearm and analyzes how much light is reflected. Think
of it like a flashlight. You push it against your skin,
and your skin glows. It’s the same principal, but
with ... an element that gives a broad spectrum of light.
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The TruTouch 1100 difference is the first noninvasive
alcohol measurement device with inherent identity
measurement that…
• eliminates the use of bodily fluids and
disposables through the use of touch-based technology
• is simple to use – total test time
in as little as 60 seconds
• the results are comparable to breath testing
• subject cooperation is limited to passive
contact |
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How It Works
The TruTouch 1100 employs near infrared spectroscopy to
measure alcohol and verify identity. The measurement involves
transmitting light into the skin via contact with an optical
fiber sensor. The reflected light is analyzed to determine
the alcohol concentration and to verify the subject’s
identity.
TruTouch has conducted numerous human alcohol dosing studies
including ones sponsored by the NIH that confirmed measurement
accuracy comparable to today’s breath technology.
Noninvasive Technology As Compared To Other
Testing Methods
Presently there are many technologies used for alcohol testing,
and all of them require: a sample of a bodily fluid, the
use of a disposable, and close supervision. Most testing
methods are cumbersome, require test subject cooperation,
and are not capable of producing simple, minimally supervised
screening with fast turnaround of test results. None can
provide identity verification as an integral part of the
test. These limitations have hampered widespread alcohol
testing from penetrating many opportunities outside of law
enforcement. The result is that the markets are underserved.
There is no lengthy observation period (as with breath devices
due to “mouth alcohol” concerns) or waiting
for results (as with blood and urine tests).
The newer technology could possibly work ok. Pulse oximeters,
by comparison, seem to work alright, albeit for a different
purpose.
Science and technology constantly advance,
with new ideas or models rising to deal with older notions
(e.g. how to full-proof deal with so many potential interferents).
In school, we learned Pluto was a planet in our solar system.
Now it is believed to be merely a rogue planetoid/asteroid/big
rock just orbiting the Sun. We used to believe it was a
planet, now it is really just a cartoon dog at Disney World.
The existence of interferants has clearly been substantiated.
The Intoxilyzers, Intoximeters & others will be replaced
as these current machines seem relatively antiquated.
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The old Intoximeter EC/IR is used for San Diego
DUI cases by San Diego CHP, San Diego County Sheriff's
Department & other San Diego County Police |
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In any event, for any machine, the so-called
mouth alcohol detector does not guarantee the absence of
mouth alcohol concentration. Only a biased or naive prosecution
expert relies on the purported detector to: a) always function,
and b) always detect mouth alcohol contamination. Which
is the reason why the manufacturer and the State of California
both still require a minimum 15 minute continuous observation
/ deprivation period prior to properly testing a San Diego
DUI arrestee.
Research further reveals the Intoxilyzer's mouth alcohol
detector is not entirely reliable, receiving readings as
high as .18% when testing subjects with dentures. "The
(mouth alcohol detector aka) slope detector was never intended
to be a substitute for residual mouth alcohol detection
and prevention protocols such as a pretest alcohol deprivation
period." [See e.g. Harding, P., McMurray, M., Laessig,
R., Simley, D., Correll, P., Tsunehiro, J., The Effect of
Dentures and Denture Adhesives on Mouth Alcohol Retention,
Journal of Forensic Science, 1992, 37:4; pp. 999-1007, p.
1006.]
The Florida Department of Law Enforcement's inspector recently
admitted that the results of several 8000 machines are scientifically
unreliable. In some cases, the Intoxilyzer 8000's print-outs
fail to disclose that an inadequate breath volume was tested
on the accused driver. An 8000 is not a perfect machine;
it's just the next numbered model in a series of older machines.
Florida Assistant State Attorney Earl Varn has asked the
courts not to accept any pleas on DUI cases involving the
newer ntoxilyzer 8000 breathalyzer. "We would ask the
court to enter a not-guilty plea," Varn stated in a
memo to Sarasota County Judge David Denkin, "and set
any new cases for a pretrial date." Varn stated that
his office needs more time to review the 8000's reliability.
Venice attorney Robert Harrison has been at the forefront
of the respectable breathalyzer challenge. "It is actually
is a very smart and prudent move by the state," Harrison
said, "because right now anybody who has been convicted
or pleads guilty has the possibility of coming back and
saying, 'I entered a (guilty) plea (after the breathalyzer
results) but the state didn't tell me they were having problems
with it." According to Laura D. Barfield, Florida Department
of Law Enforcement Alcohol Testing Program Manager, the
machine will post unreliable results if the subject does
not blow a minimum of 1.1 liters of breath into the machine
within three minutes. The software is not instructed to
report a "Volume Not Met" flag, Barfield stated,
if the subject breathes less than 1.1 liters of breath into
the machine. In a letter to the Sarasota County Sheriff's
Office which operates the county's five breathalyzers, Barfield
claims FDLE "discovered" the volume problem, when
in fact Harrison's research was responsible for uncovering
the issue. "If the state found it and didn't tell us,"
Harrrison said, "that could be an even bigger mess
which could have civil rights implications." FDLE is
responsible for breathalyzer operations in Florida. Barfield
also wrote that the anayltical functions of the 8000 are
not affected by the volume issue. She said there will be
a software revision to correct the volume problem.
Barfield said the volume problem only showed up in a "small
number of breath samples." Harrison said FDLE has discovered
at least 189 cases of Intoxilyzer 8000s reporting "suspect"
volume results. "If somebody registers a .277 and they
didn't blow into the machine (an incident supported by FDLE's
own data)," Harrison said, "that is indefensible."
Harrison pointed out breathalyzer evidence is not the only
evidence used in DUI cases. When one part of the prosecution's
evidence is not so reliable, the prosecutor has to argue
what evidence remains.
There are a number of reported 8000 problems - see http://www.duikeywest.com/secrets_of_the_intoxilyzer1.html
It is difficult to fathom why San Diego DUI law enforcement
fails to use the very best available breath testing machine
when one's San Diego DUI proof of guilt beyond a reasonable
doubt is in question.
These issues continue to be raised by an honorable San Diego
DUI Lawyer .
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San Diego County DUI Law Center
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