Marin County DUI Attorney
The Law Office of Robert Tayac
Marin County DUI Lawyer Attorney Profile Expert Profiles Testimonials Case Evaluation Contact Us
DUI Overview
What To Do First
Frequently Asked Questions
The Criminal Case
The DMV Case
First Offense DUI
Second Offense DUI
Third Offense DUI
Multiple DUI's
Field Sobriety Tests
Preliminary Alcohol Screening
Breath Alcohol Testing
Blood Alcohol Testing
DUI Accidents
DUI Penalties
Blood Alcohol Calculator
DUI Defenses
Out of State Drivers
DUI & Drug Arrests
Boats & Motorcycles
Federal DUI
DUI Schools
California Drunk Driving Defense by Lawrence Taylor and Robert Tayac
View Our Informative Videos
We accept Visa, Mastercard, American Express and Discover.

Preliminary Alcohol Screening

Preliminary Alcohol Screening is typically administered by California Highway Patrol officers or local law enforcement officers on a machine commonly referred to a PAS device.  A PAS device is a portable breath tester used by law enforcement officers following administration of so-called Field Sobriety Tests (FST's).  The most common PAS device used in Marin County DUI investigations is the Alco Sensor IV Preliminary Alcohol Screening device manufactured by Intoximeters Inc.

The Alco Sensor IV (ASIV) is a handheld breath testing device used to measure a driver's breath alcohol level at the locating of a traffic stop which has resulted in a driving under the influence investigation. PAS devices provide a means of determining a driver's breath alcohol level with a fair degree of accuracy. California law requires breath tests to be conducted in compliance with California Code of Regulations.  Title 17 is the governing section of the California Code of Regulations applicable to alcohol breath tests.

The manufacturer of the Alcosensor IV, Intoximeters, Inc. produces several alcohol detection devices. The company offers portable and stationary alcohol breath testing machines designed to determine the amount of alcohol in a person's blood indirectly. In additional to manufacturing the breath testing machines, Intoximeters provides training on the maintenance of the devices. Although, Intoximeters, Inc. is based out of St Louis, Missouri, members of the California Highway Patrol receive their training in PAS devices at the California Highway Patrol Academy located in Sacramento.  Local law enforcement officers either receive training at their respective academies, in service training or no training at all.

Early versions of the Alco Sensor were introduced in the 1970's. This device was a hand held portable alcohol screening device which was a new addition the normal equipment police officers use. The Alco Sensor product line is presently in production and is one of the most widely used alcohol screening devices available. They are commonly reffered to as Preliminary Alcohol Screening devices or PAS devices.

In the 1990's, Intoximeters Inc. began to manufacture the Alco Sensor IV. The Alco Sensor IV consisted of fuel cell technology integrated into the device. That integration is used to determine the alcohol concentration from a DUI suspect's breath. The Alco Sensor IV is available with or without a memory option. The memory option allows the device to electronically store the data which can then be transferred to a computer. To date, the Alco Sensor IV is one of the most widely used breath detection devices.

The Alco Sensor IV follows a software driven test protocol. Each function is displayed on an LED display which provides the operator with step-by-step instructions for administering a breath alcohol test. The device automatically samples deep lung breath and is programmed to display the result in a three digit readout in California (two or four digits where required). Inserting the plastic mouthpiece powers the instrument ON and depressing the release button which ejects the mouthpiece turns the instrument OFF.

Law Governing Preliminary Alcohol Screening (PAS) Devices

There are specific laws and regulations governing the admissibility of results obtained on the Alco Sensor IV Preliminary Alcohol Screening device.  In the State of California, Alcohol breath testing is governed by Title 17 of the California Code of Regulations.  Additionally, California appellate court decisions control foundational issues which must be satisfied before the numerical result from a Preliminary Alcohol Screening device may be introduced in court or at a DMV Hearing.  The California Court of Appeal decided People v. Adams in 1976, while in 2002, the California Supreme Court decided People v. Williams.  These two cases stand for the general proposition that before the numerical results of any Preliminary Alcohol Screening device may be admitted, the Marin County prosecutor or California DMV Hearing Officer must establish: 1) the PAS was in proper working order; 2) the PAS test was properly administered; and 3) the investigating officer was competent and qualified to administer the test.

Alco Sensor IV Warranty

Although most Alcosensor IV Preliminary Alcohol Screening devices have been in service for several years, Intoximeters Inc. limits the warranty to a period of twelve (12) months from the original date of purchase.

California PAS Devices

    Alcosensor III

    Alcosensor IV

    Drager Alcotest 7410 (EPAS)