Section V Administrative / Maintenance Functions; Overview; Accuracy Check Methods; Approved Dry Gas Standard - Intoximeters Alco-Sensor FST Operator's Manual

ALCO-SENSOR FST
SECTION V
ADMINISTRATIVE / MAINTENANCE FUNCTIONS

Overview

To obtain accurate subject test results, the unit must be properly calibrated.
The accuracy of an instrument is verified by running a known alcohol concentration (standard) through the Alco-
Sensor FST sampling system, and verifying that the result is within an acceptable tolerance of the expected or
target value of the standard. This is called an accuracy check. It is also sometimes called quality assurance or a
calibration check. The terms are used interchangeably; however, we will use the term accuracy check in this
manual.
When performing an accuracy check, if the result of the accuracy check is within an acceptable tolerance of the
stated value of the standard, the Alco-Sensor FST is considered calibrated. If the reading is not within the
acceptable tolerance the Alco-Sensor FST must have its calibration adjusted. Only Intoximeters approved
standards (dry or wet) gas samples with a known expected ethanol concentration should be used to perform the
accuracy check or calibration procedure.
Alco-Sensor FSTs hold calibration for months. However, some users choose to perform an accuracy check once a
week during the first month the unit is in use. This process helps establish that the new instrument is stable and
increases the operator's confidence in its accuracy.
Intoximeters recommends you follow your own policy when performing accuracy checks. If you do not have a
quality assurance policy and if an accuracy check has not occurred within the past 31 days, it is recommended that
an accuracy check be run in conjunction with a subject test to ensure the instrument has maintained proper
calibration.

Accuracy Check Methods

Intoximeters recommends that external accuracy checks and calibrations be performed using a dry gas standard
approved for use by both NHTSA and Intoximeters or a wet bath simulator with properly certified and maintained
ethanol solutions. The wet bath simulator should be approved for use by NHTSA and Intoximeters.
In all cases the compressed gas tanks, simulators and simulator solutions should be used and maintained only in
accordance with the quality assurance plans provided by their respective manufacturers.
Although some jurisdictions require using certified standards with specific values to perform accuracy checks and
calibrations, these values are imposed only by the specific jurisdiction. The analytical design of the instrument
allows it to be checked for accuracy and calibrated using positive standard values between .015 and .200 g/210L.

Approved Dry Gas Standard

ELEMENTS:
A.
B.
C.
MAKEUP:
CHARACTERISTICS:
A. Flow rate of the regulator must be 6 liters per minute for automatic sampling on Accuracy
Checks and Calibrations. 1.5 liter per minute regulators can be used, but manual sampling
on Accuracy Checks and Calibrations will be required. (1.5 LPM regulators purchased from
Intoximeters can be modified in the field to become 6 LPM regulators – contact Intoximeters
Customer Support for more information (314) 429-4000)).
B. Follow instructions on the tanks to mount the regulator. When the regulator is initially
mounted, depress the regulator control button and allow the gas to purge the valve for 10
seconds.
Pressurized NHTSA and Intoximeters approved dry gas tank.
Small single staged approved regulator
6 LPM regulator required for automatic sampling
1.5 LPM regulator is acceptable, but manual sampling will be required
TRUE-CAL II device. (Optional)
NIST traceable tank contains a single-phased mixture of Nitrogen and Ethanol.
Alco-Sensor FST Operator Manual, Page 22 of 33, 11/30/2017