Arizona
Breath Tests
Theses
breath testing contraptions are the "Scud Missiles" of
law enforcement. They are notoriously inaccurate and they injure
innocent people!
There
are three major types of breath testing devices, and each is based
on a different principle.
- Breathalyzer
- Uses a chemical reaction involving alcohol that produces a color
change
- Intoxilyzer
- Detects alcohol by infrared (IR) spectroscopy
- Alcosensor
III or IV - Detects a chemical reaction of alcohol in a fuel cell
Regardless
of the breath test type, each device has a mouthpiece, a tube through
which the suspect blows air, and a sample chamber where the air
goes. The rest of the device varies with the type.
Breathalyzer
To
measure alcohol, a suspect breathes into the device. The breath
sample is bubbled in one vial through a mixture of sulfuric acid,
potassium dichromate, silver nitrate and water. The principle of
the measurement is based on a chemical reaction created by interaction
between the breath tests and the substances listed.
Intoxilyzer
This
device uses infrared spectroscopy, which identifies molecules based
on the way they absorb infrared light. As a breath analyzer, the
intoxilyzer calculates the BAC based on the absorption of infrared
light.
Alcosensor
III or IV
Modern
fuel-cell technology (which may power our cars and even our houses
some day) has been applied to breath alcohol detectors. Devices
like the Alcosensor III and IV use fuel cells. Police officers can
carry portable breath testing devices (like the Alcosensor) that
use the same principle as full-size devices. Court cases can turn
on the Intoxilyzer
5000 Weaknesses, however, so prosecutors rely on
the results obtained from full-size devices.
Manuals and Studies
IR 8000 Manual Part 1
IR 8000 Manual Part 2
Tennessee Study
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