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Alco Sensor III Preliminary Alcohol Screening (PAS) Device


The Alco-Sensor III manufactured by Intoximeters is a pocket sized, hand-held, 3 digit display, portable (weighing 6 ounces), preliminary alcohol screening device intended for use by members of law enforcement, including the California Highway Patrol, local police officers and sheriff's deputies are interested in securing a breath alcohol measurement at at the scene of a traffic stop. The instrument is considered an evidential breath testing device by the United States Department of Transportation (DOT), but not by any California State Court.

This breath testing device has been approved by the National Highway Traffic Safety Administration (NHTSA), however, is not approved as an evidential breath alcohol testing device in California. Although the Alco Sensor III has been replaced by the newer Alco Sensor IV, the Alco Sensor III remains a Preliminary Alcohol Screening (PAS) device in California used by the California Highway Patrol and other law enforcement agencies.

How the Alco Sensor III Works

The Alco Sensor III utilizes an electrochemical sensor (fuel cell) to quantify alcohol in the sample provided by the driver suspected of driving under the influence. The fuel cell is a porous disk with a thin layer of platinum black on both faces. The platinum black disk is saturated with an electrolyte and mounted in a valve assembly that is designed to draw a fixed volume sample across the surface of the fuel cell. When a breath sample is drawn across the top surface of the cell, any alcohol coming in contact with the cell's surface is broken down chemically. The manufacturer claims the device is capable of operating between 0° and 40° C.

For each molecule of alcohol that is broken down a given number of electrons are freed during the process. The number of electrons generated are in proportion to the amount of alcohol in the sample. By measuring the number of electrons (the resulting electrical signal) a digital BrAC (Breath Alcohol Concentration) is calculated and reported. The manufacture, Intoximeters, Inc., represents the fuel cell will last for two (2) to five (5) years without replacement.

Fuel cell sensors are sensitive to alcohol and do not respond to acetone or other substances which are found in the breath. Intoximeters represents that the Alco-Sensor III can accurately detect breath alcohol levels between .000 - .400 BrAC. The unit can run negative tests every 15 to 20 seconds. It can be run every two minutes on positive tests and is limited to five positive tests (.100) in an hour before re-calibration is required. The United States Department of Transportation has approved the Alco Sensor III for evidential use.

The Alco Sensor III is powered by a 9 volt alkaline battery, which the manufacturer represents is sufficient to administer 300 between battery changes and the unit is equipped with a low battery indicator. This Preliminary Alcohol Screening device has a large, three digit display mounted on the front of the device and manufacturer claims it will read accurately at low levels. The Alco Sensor III is also capable of sampling an unconscious person, but it is questionable as to whether safeguards related to mouth alcohol contamination are properly addressed. The operator administering a breath test on the Alco Sensor III can manually trap a sample.

Accuracy and Precision of the Alco Sensor III

The manufacture claims the Alco Sensor III will maintain calibration (plus or minus .005 at the .100 level) for months. However, California requires accuracy checks every ten (10) days or 150 tests. Checks and calibrations may be performed with an approved wet bath simulator or a dry gas standard.

Warranty of the Alco Sensor III

Unless otherwise determined by the purchase agreement Intoximeters, Inc. warrants to the original user-purchaser that all new Intoximeter Breath Alcohol Analyzers are free from defects in material and workmanship, under normal use and service, for a period of twelve (12) months from original invoice date. The following are not covered under this warranty: consumables or supplies (i.e. mouthpieces, calibration gas, ink ribbons, printer paper) nor any damage which has, in Intoximeters Authorized Sales/Service Outlet opinion, been the result of misuse, alteration, accident or abnormal conditions of operation or handling. Also excluded from coverage under this agreement are printers and other hardware that are not manufactured by or for Intoximeters Inc. and do not carry the Intoximeters trademark, trade name, or logo affixed to them.

Software is warranted to perform substantially in accordance with the accompanying written materials. Software is warranted to be free from defects in materials and workmanship under normal use and service for a period of twelve months from original invoice date.

If the product, under warranty, is returned to an Intoximeters Authorized Service Center and, upon examination, it is determined to be defective, Intoximeters Authorized Sales/Service Outlet obligation is limited to repair, replacement or refund of purchase price. Intoximeters Authorized Sales/Service Outlet reserves the option to choose repair, replacement or refund as the means to satisfy this obligation.

CAUTION: The Intoximeter Breath Alcohol Analyzers contains static-sensitive memory devices. The unit’s casing should only be opened by a factory authorized technician.

This warranty does not apply if: the product has been repaired or modified by someone other than a factory authorized technician without written permission from Intoximeters; if parts other than Intoximeters approved parts are used in replacement or repair; or if any Intoximeters serial number has been removed or defaced.

For warranty service, contact your nearest Intoximeters Authorized Service Center to obtain an authorization return number and the address of the closest repair center. The product should be sent to the Service Center with a description of the difficulty (postage and insurance prepaid). Intoximeters Authorized Sales/Service Outlet assumes no risk for damage in transit. Intoximeters Authorized Sales/Service Outlet will pay return postage for a product repaired under warranty.

If Intoximeters Authorized Sales/Service Outlet determines that the failure was caused by misuse, alteration, accident or abnormal condition of operation or handling, Intoximeters Authorized Sales/Service Outlet will provide an estimate of repair costs before the repairs are made. Following repair, the product will be returned to the purchaser via ground transportation prepaid (overnight or express delivery charges are additional), and the purchaser will be billed for the repair and the shipping cost.

Repaired components are warranted for a period of 90 days from the billing date of the repair. The warranty on repaired components are subject to the same limitations as this warranty. Components not repaired or replaced do not receive an extended 90 day warranty.

Warranty service is available outside the United States only on products purchased through an Intoximeters Authorized Sales/Service Outlet in the country of use, or if the Purchaser has paid the applicable Intoximeters international price. If Purchaser transports a product from the United States without having paid the applicable Intoximeters price, the product must be returned to the United States to receive warranty service. Purchaser shall pay for transportation to the service center and shall bear the risk of loss or damage in transit for all products so returned to the United States. Intoximeters reserves the right to invoice the Purchaser for importation costs of repair/replacement parts when the product purchased in one country is exported and submitted for repair or service in another country.


Note: Some countries or states do not allow the foregoing limitations. Other rights may also vary.

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