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Instrument Maintenance

Maintain your Intoximeters instrument for long-lasting reliability, and for a strong testing program.


QA Methods

Quality Assurance Plan

All breath alcohol testing programs should follow criteria set forth in a Quality Assurance Plan, which may also be referred to as a Maintenance Protocol or Maintenance Plan.  The QAP may designate the types of standards that may be used to perform calibrations and accuracy checks, and the minimum intervals for performing calibrations and accuracy checks. The QAP might also specify the acceptable tolerance to determine if the instrument is in proper calibration (often +/- 10% in screening applications). Recommended or required inspection and maintenance intervals may be part of the QAP as well.

It is important to understand that the QAP is designed for a specific testing program.  Intoximeters has developed a QAP approved by NHTSA (National Highway Traffic Safety Administration) for instruments used for US DOT Workplace testing purposes. These guidelines are required by the DOT Workplace testing rules in 49 CFR Part 40.233.

For your program, the Operators manual offers some basic guidelines to help develop your protocols but you can consult a local authority or contact Intoximeters for more specific information.

Accuracy Check Methods
Breath alcohol testing instruments are calibrated and checked for accuracy utilizing an ethanol standard with a known alcohol concentration.  There are two types of standards that are widely accepted and commonly used:


The value of the Standard used is usually determined by  Quality Assurance Plan (QAP).  For example, law enforcement agencies that arrest drunk drivers based on a legal limit of  0.080 BrAC will typically check their evidential breath alcohol testing devices with a standard that has a target value at or near 0.080 BrAC.  Many law enforcement agencies also use 0.100 standards.   The NHTSA (National Highway Traffic Safety Administration) approved Intoximeters QAP required to be used in conjunction with US DOT Workplace testing (49 CFR Part 40.233) designates standards with a stated equivalent value between 0.020 and 0.040.

Fuel Cell sensors are linear output devices and can thus be calibrated for the dynamic range of readings at any point within that range.  Similarly, these devices can also be checked at any point to determine that they are in calibration throughout the entire range of readings. As a result, an instrument calibrated at one level will also be calibrated for other applications that have a need to check samples for yet another level.

Definitions Of Terms


A Standard – Also called an Ethanol Standard or Gas Standard.  A solution of ethanol in water (wet standard) or mixture of pressurized gas, usually ethanol in nitrogen (dry standard) certified to produce a sample containing a predictable alcohol concentration.

Expected Value/Target Value – The result expected to be reported from the standard at the time of the accuracy check or calibration.

Quality Assurance Plan (QAP) – A set of criteria established by the manufacturer of the instrument and/or a testing program manager that establishes parameters for conducting accuracy checks and calibrations under a given testing program.

Calibration Log – A record of accuracy checks and calibrations performed on a specific breath alcohol testing instrument.

Accuracy Check – Also called a “Calibration Check” or “External Calibration Check”. Checking an instrument for accuracy against a known standard.  This process is much the same as running a sample on a subject, but in this case the operator knows what result the instrument should produce. It only checks to see that given a known gas value registers correctly within tolerances defined by your testing protocol.

Calibration Adjustment – Setting (adjusting) an instrument’s sensitivity to properly report the known value of a standard.  The procedure is only done when your instrument’s Accuracy Check result falls outside of the acceptable tolerance level stated in your QAP.  All calibrations should be followed by an Accuracy Check to ensure that the adjustment is correct.

Accuracy Check Tutorial
Accuracy Check Tutorial Overview
This section of the Intoximeters website is designed to offer users an online step by step guide for completing an accuracy check on several of our most commonly used instruments. This tool offers definitions of the key terms and pictures of step by step procedures to help you properly check your instrument(s).


What is an Accuracy Check

Accuracy Check (also called “Calibration Check”, or “External Calibration Check”)

Checking an instrument for accuracy against a known standard.  This process is much the same as a running a sample on a subject, but in this case the operator knows what result the instrument should produce . The only other difference is that on an Accuracy Check the sample is almost always taken manually after several seconds of flow from the gas standard, but while the gas vapor is still flowing,The results of an accuracy check must fall within an acceptable range for the instrument to be considered “in calibration”.  An accuracy check result outside the acceptable tolerance may throw into doubt the validity of test results and as a result, a calibration is suggested following a failed accuracy check. Once the calibration has been completed an accuracy check should be run to verify that the calibration was successful.

Tutorial for performing an Accuracy Check
Select the process you wish to learn more about:


Calibration Adjustment Tutorial


Calibration Adjustment Tutorial Overview
Here we offer users an online step by step guide for calibrating several of our most commonly used instruments. This tool offers definitions of the key terms and an animated Step by Step procedure to help you properly calibrate your instrument(s).


Although this information appears in the instrument manual, some testing programs only allow certain qualified operators to perform accuracy checks and calibrations. For example, the DOT regulations for Workplace Testing require that “calibration of the EBT are performed by the manufacturer or a maintenance representative certified by the device manufacturer or a state health agency or other appropriate state agency.” 

Before performing calibrations, make sure that you are qualified to perform this function under the rules of your program.

What is a Calibration?
Calibration: The setting or adjusting of an instrument’s sensitivity to properly report the known value of a standard. All calibrations should be followed by an Accuracy Check to ensure that the adjustment is correct.  Calibrations should only be done by a trained Calibration Technical or Intoximeters Repair Technician.  Calibrating an instrument is not a common or routinely performed task. It should only be done after a failed Accuracy Check.

A “Calibration Check” is not a Calibration.  Please refer to the Accuracy Check Tutorial section above if you are attempting to perform this type of check.

Tutorial for performing a Calibration
Select the process you wish to learn more about:


Erase Instrument Procedures

Erasing Test Data Overview

Instruments built by Intoximeters that offer memory capabilities and do not offer a FIFO (First In First Out) memory option will require the erasure of test data once the memory capacity is reached.

If it is important that the user maintain a record of all test data performed on the instrument, prior to erasing the memory, either making a hard copy of the stored data or uploading the data to a compatible database software package will allow permanent storage for record keeping purposes.

Depending upon the instrument that you are using, a Windows based database software program such as “Total Recall” (compatible with – ASIV w/Memory) or “IntoxNet” (compatible with Total Recall Software, @Work Software, RBTIV, AMCC, ECIR, ECIR II) are available through Intoximeters, Inc. If you need additional information or wish to purchase the software contact Intoximeters Customer Support.

Tutorial for performing an Erase Procedure
Specific instructions for erasing test memory are available in your Operator’s Manual. Below are several links to step by step procedures for performing a memory erase function. Click on the name of the instrument that you are interested in learning more about and follow the instructions. If you have trouble with these instructions you are welcome to contact Intoximeters Customer Support.

There is no undo for these tasks.  Erasing an instrument’s data is permanent.  There is no way to retrieve erased data from an instrument.  Please backup your data before doing any of these procedures.



Cleaning and Disinfecting

GENERAL CLEANING: Use of a damp cloth is an acceptable method on exterior surfaces of the instrument. Special attention needs to be paid when cleaning the instrument so that moisture does not get onto the electronic circuit boards or into the internal sample path. There are certain disinfectant products that can be used. For more information, see the attached Cleaning Guidelines document. For information on cleaning and disinfecting your handheld Intoximeters instrument, see the Cleaning and Disinfecting document (updated March, 2020). 


Intoximeters, Inc. does not claim to be an expert on infectious disease transmission, but it has developed two guides (Infection Control Cleaning and Disinfecting Intoximeters Handheld Instruments and Infection Control Cleaning and Disinfecting an Intoximeters Desktop Instrument)  that list some of the concerns and commonsense steps that can be taken to reduce the likelihood of disease transmission while performing a breath alcohol test or while cleaning or disinfecting an Intoximeters, Inc. alcohol breath test instrument.

Additional information and directives on Coronavirus can be found through OSHA (3990-03 2020) or the CDC. The CDC has put out documentation for the maintenance on other types of breathing related equipment such as spirometers that may have helpful information on infections control measures.


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