Southern California DUI Defense Home
Our DUI Defense Team
10 Tips if You Get Stopped for DUI
DUI FAQs
30 Ways To Fight Your DUI
Web Resources
CHP DUI Manual

DUI Breath Test Machines

Most citizens arrested for DUI in California opt for a breath alcohol test. A series of different DUI breath test machines are used by the various Southern California counties. An experienced California DUI defense attorney can challenge the reliability of any of these alcohol breath testing devices.

BAC DataMaster
The BAC DataMaster is used for all Los Angeles County DUI cases (excluding those in the cities of Los Angeles and Long Beach)

Intox EC/IR
The Intox EC/IR is used for DUI cases in the City of Los Angeles

Draeger Alcotest 7110
The Draeger Alcotest 7110 is used for San Bernardino and Riverside County DUI cases. More information about the Draeger Alcotest 7110

Draeger Alcotest 7410
The Draeger Alcotest 7410 is used for Orange County DUI cases

Intoxilyzer 5000
The Intoxilyzer 5000 is used for Long Beach DUI cases

Intoxilyzer 8000
The Intoxilyzer 8000 is used for San Diego DUI cases

Each of the DUI breath test machines attempts to measure the concentration of alcohol in the deep lung region called the "alveoli." The concentration of alcohol in the "alveolar air" is thought to correspond to the concentration of alcohol in the blood. In theory, then, a person's breath alcohol level will roughly approximate his/her blood alcohol level.

The DUI breath test devices employ one or both of two technologies: (1) infrared spectroscopy or (2) fuel cell (electrochemical oxidation). Unfortunately, both of these DUI breath testing methods is deeply flawed and plagued with problems that can lead to the wrongful prosecution (and conviction) of innocent DUI defendants.

DUI Breath Testing & Infrared Spectroscopy

Most DUI breath test devices today use "infrared spectroscopy" as their means of measuring breath alcohol levels. The underlying idea is that all chemicals (including alcohol) absorb infrared radiation at specific wavelengths. Ethyl alcohol absorbs strongly in the infrared wavelength range of 3.3 to 3.5 microns, and also at 9.5 microns.

The DUI breath machines using infrared spectroscopy shoot infrared energy through a sample chamber. The suspected drunk driver blows into the sample chamber. The amount of infrared energy lost due to absorption by ethyl alcohol molecules is thought to be proportionate to the DUI suspect's breath alcohol concentration.

DUI Breath Testing & Fuel Cell Devices (Electrochemical Oxidation)

A fuel cell is a machine intended to constantly convert fuel and an oxidant into a direct current. With DUI breath test machines, alcohol (in the breath sample blown into the machine) is used as the fuel and oxygen from the atmosphere as the oxidant.

Through a process called electrochemical oxidation, the fuel cell converts alcohol to acetic acid. This generates two electrons for each alcohol molecule. These electrons spark an electric current that is thought to measure the amount of alcohol in the DUI suspect's breath sample.

Copyright © 2008 Neil Shouse & Associates - Southern California DUI Defense Attorneys - California Drunk Driving Defense Lawyers. All rights reserved.

California DUI Defense Lawyers Disclaimer: The DUI Defense, Drunk Driving, DMV Drivers License Suspension, Driving Under the Influence, Driving While Intoxicated or other DUI defense information presented at this site should not be considered formal legal advice nor the formation of a lawyer or attorney client relationship. Any results set forth here were dependent on the facts of that case and the results will differ from case to case. Please contact a California DUI defense lawyer or attorney for a free initial consultation. This web site is not intended to solicit clients for matters outside of the State of California.

Our DUI defense law firm serves the following Southern California communities, among others: Los Angeles County, Agoura, Alhambra, Bellflower, Beverly Hills, Burbank, Calabasas, Century City, Chatsworth, Compton, Culver City, Diamond Bar, Downey, El Segundo, Encino, Glendale, Glendora, Hermosa Beach, Hidden Hills, Hollywood, Huntington Park, Inglewood, Los Angeles Lawyer, La Canada, Long Beach, Los Angeles Attorney, Malibu, Manhattan Beach, Marina Del Rey, Norwalk, Palos Verdes, Pasadena, Pomona, Rancho Palos Verdes, Redondo Beach, Rolling Hills, San Dimas, San Fernando, San Marino, San Pedro, Santa Clarita, Sierra Madre, Santa Monica, South Gate, South Pasadena, Sylmar, Torrance, Universal City, Valencia, Van Nuys, West Covina, West Hollywood, Walnut, Westchester, Westlake Village, Whittier, Woodland Hills, Orange County, San Bernardino County, Ontario, Rancho Cucamonga, Fontana, Redlands, Upland, Riverside, Corona, Norco, Santa Barbara County, and Santa Barbara.