Field Sobriety Tests
Phone: (619) 237-0384 Fax: (619) 237-0109
110 West C Street, Suite 1400 San Diego, CA 92101
110 West C Street, Suite 1400 San Diego, CA 92101
BREATH ALCOHOL TESTS TO DETERMINE DUI
BreathAlcohol Concentration as a Chemical Test Option in CaliforniaWebsite Created by San Diego DUI Lawyer G. Cole Casey
AN EXCLUSIVE DRUNK DRIVING DEFENSE FIRM
San Diego Police
officers often use simple breath-testing machines to first test what a suspected drunk drivers' blood alcohol level is. Many of us have
heard about or read about a driver who had been charged with drunk driving in San Diego. Someone suspected of drunk driving in California will be pulled
over and administered a roadside sobriety test. The DUI test will consist of actions such as touching your nose or walking in a
straight line. Even if a San Diego DUI suspect's motor skills aren’t affected by alcohol, a drunk driving suspect can still be convicted of drunk driving in San Diego due to their
blood alcohol content ratios. Recent San Diego DUI laws have severely targeted San Diego County drunk drivers because alcohol related accidents have become one of
the most common forms of traffic deaths in the the region. In 1999, 38% of all traffic related deaths in San Diego were cause by
alcohol. Not a lot of San Diego motorists understand the legal limit of blood alcoho, or how it can be measured. The legal limit
for blood alcohol in San Diego is .08%. A San Diego DUI suspect's blood alcohol level can be tested by instruments which will be discussed below.
When alcohol enters your body, there are many ways to tell just how much alcohol is flowing through your system. The original method used in San Diego to check for DUI was to test your blood. This drunk driving test showed that many people began to have mental and physical impairment around .05% blood to alcohol concentration; or otherwise known as BAC. A persons BAC can tell a lot about what their body is doing or going to do. Many people are found unconscious when their BAC reaches .4%. As a persons BAC reaches .5%, they are known to be flirting with the very thin line between unconsciousness and death. Although very accurate, the technique of testing a San Diego DUI suspect's BAC using blood is now very unpopular. Testing a suspected drunk driver's blood can be very time consuming and costly.
In the 1930’s it was established that the alcohol content found in a persons blood stream could be read by testing the alcohol on that persons breath. This discovery helped create what we now know as the breathalyzer. The breathalyser or breathalyzer, are both trademarked names that are owned by Intoximeters, Inc. The breathalyzer was invented by R.F. Borkenstein and was originally introduced in 1954. Mr. Borkensteins instrument is still widely used today in San Diego County DUI, drunkd driving, and DWI cases. It has been known to be a quick, easy, painless and highly accurate way to test someone’s BAC at a very low cost. In San Diego, a trained operator is required to give the test, but collections of the results are very simple. The ability to test alcohol by using breath influenced many jurisdictions to define alcohol in terms of breath instead of blood. Thus calculations based on blood are often no longer necessary.
When alcohol enters your body, there are many ways to tell just how much alcohol is flowing through your system. The original method used in San Diego to check for DUI was to test your blood. This drunk driving test showed that many people began to have mental and physical impairment around .05% blood to alcohol concentration; or otherwise known as BAC. A persons BAC can tell a lot about what their body is doing or going to do. Many people are found unconscious when their BAC reaches .4%. As a persons BAC reaches .5%, they are known to be flirting with the very thin line between unconsciousness and death. Although very accurate, the technique of testing a San Diego DUI suspect's BAC using blood is now very unpopular. Testing a suspected drunk driver's blood can be very time consuming and costly.
In the 1930’s it was established that the alcohol content found in a persons blood stream could be read by testing the alcohol on that persons breath. This discovery helped create what we now know as the breathalyzer. The breathalyser or breathalyzer, are both trademarked names that are owned by Intoximeters, Inc. The breathalyzer was invented by R.F. Borkenstein and was originally introduced in 1954. Mr. Borkensteins instrument is still widely used today in San Diego County DUI, drunkd driving, and DWI cases. It has been known to be a quick, easy, painless and highly accurate way to test someone’s BAC at a very low cost. In San Diego, a trained operator is required to give the test, but collections of the results are very simple. The ability to test alcohol by using breath influenced many jurisdictions to define alcohol in terms of breath instead of blood. Thus calculations based on blood are often no longer necessary.
Breath Alcohol
Fuel Cell Design
Blood Alcohol Chemistry
Serum Testing Alternative
Breath Testing Instruments
The Path of Alcohol in the Breath
Liver Heart Lungs
"It is in the lungs that the respiratory system bridges with the circulatory system so that oxygen can enter the blood and carbon dioxide can leave it... It is at the surface of the alveolar sacs that blood flowing through the capillaries comes in contact with fresh oxygenated air in the sacs... If, while this exchange is taking place, alcohol or any other volatile substance happens to be in the blood, it too will pass into the alveoli... (Criminalistics 262). "
HENRY'S LAW
In a closed container, at a given temperature and pressure a material in solution will be in equilibrium with air in the space
above. Ethanol at 34° C is in equilibrium with blood at a ration of 2100: 1. Alcohol's distribution between blood and breath
from the deepest part of the lung obeys Henry's Law. This means that 2100 ml of alveolar air will contain the same amount of
alcohol that is present in 1 ml of the blood with which it has come to equilibrium.
Fuel Cell Design
If an instrument uses a fuel cell, it will absorb the alcohol from ones breath, oxidize it and produce an electrical current
that shows a proportional quantity of alcohol present in the breath.
In the 1800’s the theory of fuel cell effect was conceived. The science in getting a reaction to create a flow between
electrodes was to take platinum electrodes in sulfuric acid and supply hydrogen to one electrode and oxygen to the other thus
generating a current stream between the electrodes.
In the 1960s innovative breakthroughs led to a fuel cell that can be specific for alcohol. The 1970’s brought further
advancement in the area via newly available fuel cell breath analyzers which could were used commercially; many are still used
today.
The Chemistry of Alcohol
Alcoholic beverages contain a substance called ethyl alcohol (ethanol). The anatomy of ethanol is exhibited below:
H 3C - C - O - H
H
C stands for carbon,
H: hydrogen,
O: oxygen and each hyphen is a chemical bond between the atoms.
The OH (O-H) faction of the molecule creates the substance alcohol.
carbon-carbon (C - C)
carbon-hydrogen (C - H)
carbon-oxygen (C - O)
oxygen-hydrogen (O - H)
Chemical bonds can and will bend and stretch like rubber bands, this property makes it possible to detect ethanol in a sample by means of infrared (IR) spectroscopy.
One device commonly used in determining DUI in San Diego is called an Intoxilyzer. The Intoxilyzer is used to identify molecules based on the way they absorb IR light is known as an Intoxilyzer. A molecule will constantly vibrate and IR light will change the vibration, the change of vibration will bend and stretch bonds like rubber bands. (The chemical bonds mentioned earlier).
Each type of bond within a molecule absorbs IR at different wavelengths. Accordingly, to identify ethanol in a sample, you have to look at the wavelengths of the bonds in ethanol (C-O, O-H, C-H, C-C) and calculate the absorption of IR light. The absorbed wavelengths aid in identifying the substance as ethanol. The quantity of IR absorption discloses how much ethanol is present.
Serum As A Testable Alternative
The water component of blood is called Serum. Serum is created when all clotting and cells are taken from the blood. There are
many differences between serum and whole blood. Whole blood contains many items such as lipids and proteins and while its
water content will reach close to 90% the content of both plasma and serum is closer to 100%; (settling in around 98). If at
any time there is the extraction of cells; it will lead to yielding the plasma. Any additional extraction of clotting factors
will lead to yield serum. It has been found that ethanol will be elevated in these fractions because of its high percentage.
The ratio of ethanol in serum to ethanol in whole blood ranges from 1.09:1 to 1.18:1. These ratios denote that the level of
ethanol will be between 9-18% higher in serum.
While the State of Indiana’s blood alcohol tests refer simply to "blood", the courts have construed this as whole blood
(Indiana Code sections 9-30-5-1, 9-30-6-6, 9-30-6-15 and 9-30-7-4). The State Department of Toxicology uses whole blood for
alcohol testing. Nevertheless, they have been known to take tests based on the serum fraction alone. The results from serum
will have to be altered to parallel values for whole blood. If you reduce serum ethanol concentrations by 15-18%, a legitimate
method to figure out the whole blood ethanol levels is viable. The higher percentage of average serum is helpful to the
defendant given that a lower blood ethanol concentration will be found and the whole blood value will be below 20% which has
been known to be the upper limit of average serum.
To convert serum to whole blood ethanol concentration the following formula should be used.
serum ethanol x 0.8 = whole blood ethanol
whole blood ethanol/0.8 = serum ethanol
Other information regarding ethanol concentrations in whole blood and blood fractions can be found in these sources:
1. Winek, C.L. and Carfagna, M. Comparison of Plasma, Serum and Whole Blood Ethanol Concentrations. J. Analytical Toxicology.
11, 267-268, 1987.
2. Montgomery,M. R. and Reasor, M J. Retrograde Extrapolation of Blood Alcohol An Applied Approach. J. Toxicology and
Environmental Health. 36,381-392,1992.
3. Caplan, Y. H. in Medicolegal Aspects of Alcohol (J. C. Garriott, ed.), Lawyers &Judges Publishing Co., Tuscon, AZ, 1996,
pp. 137-150.
Blood Alcohol Conversion:
Blood: Serum 1: 1.20
Blood: Plasma 1: 1.20
Instruments
There are three major types of breath alcohol testing devices in use in San Diego to determine DUI, DWI, and Drunk Driving,
each based on different principles:
BREATHALYZER
Uses a chemical reaction involving alcohol that produces a color change.
To measure alcohol, a San Diego DUI 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 sulfuric acid eliminates the alcohol from the air and into a liquid solution. The potassium dichromate reacts
with the alcohol to produce chromium sulfate, potassium sulfate, acetic acid and water.
The silver nitrate acts only as a catalyst, causing the reaction to go faster while not participating in it. The
sulfuric acid also serves the purpose of providing the much needed acidic condition for this reaction.
It is during this reaction which the color change occurs that is crucial for identifying a San Diego DUI suspect's BAC.
The
reddish orange dichromate ion changes color to green chromium ion when alcohol is present; the degree of color change is
directly correlated with the amount of alcohol expelled air. The “reacted” part of the mixture is then weighed against a vial
of unreacted mixture in the photocell system. This creates an electric current that in turn moves the machines gauging needle
from its resting place. The operator must then use knobs on the machine to return the needle back to the resting place; the
more the operator has to turn the knobs, the greater the level of alcohol.
INTOXILYZER
Detects alcohol by infrared (IR) spectroscopy
An Intoxilyzer contains a lamp which generates a broadband (multiple-wavelength) IR beam. The broad band IR beam
passes through the sample compartment and is centered by a lens onto a revolving filter wheel.
The filter wheel is composed of narrow band filters specialized for the wavelengths of the bonds in ethanol.
Light, which passes through each filter, is identified by the photocell, where it is transformed to an electrical pulse.
Next, the electrical pulse is transmitted to the microprocessor which in turn deciphers the pulse and estimates the
BAC based on the absorption of infrared light.
ALCOSENSOR III or IV
Detects a chemical reaction of alcohol in a fuel cell
The Alcosensor III and IV both use fuel cells; fuel cell technology is being researched as a possible fuel for both
our cars and our homes some day. Fuel cells consist of two platinum electrodes with a porous acid-electrolyte material
inserted between them. As the suspect exhales air it travels past one side of the fuel cell, the platinum oxidizes any alcohol
in the air to create acetic acid, protons and electrons. This is referred to as the oxidation of alcohol and is the basis for
this type of BAC testing. The more alcohol that becomes oxidized, the greater the electrical current. A microprocessor is
then used to measure the electrical current and calculate the BAC.
Regardless of the type, each device has a mouthpiece, a tube through which the San Diego DUI suspect blows air, and a sample chamber where
the air goes. The rest of the device varies with the type.
G. Cole Casey heads the top San Diego drunk driving defense law firm. As a well known San Diego DUI lawyer, his proven track record and DUI jury trial case results are unmatched and unprecedented by any other DUI attorney in the region.
Call us twenty four hours a day at (619) 237-0384 or Email Us now to discuss a legitimate and effective defense strategy for your driving under the influence case.
Chemical Tests
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The Law Offices of San Diego DUI Lawyer G. Cole Casey, Esq. 110 West C Street, Suite 1400 San Diego, CA 92101 Tel
619.237.0384