Alco-Sensor III Calibration

Prior to calibrating an Intoximeters breath alcohol testing instrument, you should be trained to perform the calibration functions as allowed under your specific testing program. The calibration procedures below are designed to help you ensure precise and accurate test results. If, according to your program, you are not authorized to perform calibrations, please see your program administrator to determine the proper course of action.

DO NOT perform this procedure unless you are authorized to do so. 

Below are basic calibration instructions for the Intoximeters Alco-Sensor III breath testing instrument.

Tools Required: Before beginning have these items available: instrument, calibration standard, new mouthpiece, non-metallic screwdriver.

  • Dry Gas Standard & Regulator
  • Alco-Sensor III
  • New Mouthpiece
  • Screw Driver
  • True-Cal, True-Cal II or Elevation Chart



Note: A calibration standard can be a: 
  • Mini-Alco Can (for non-evidentiary testing applications only),
  • Dry Gas Cylinder and Regulator
  • Wet Bath Simulator and Solution

For this demonstration, a dry gas cylinder is used as the standard –value (at sea level) of .082%. a True-Cal Device was used to give the true value of the standard at the time of our demonstration – the True-Cal will adjust the expected gas value for the current atmospheric pressure. Therefore, the target value for this demonstration is .080.

When to Perform a Calibration

A calibration procedure should be performed when the result of an accuracy check indicates the unit does not read a standard within your testing program`s specified acceptable tolerance.

True-Cal displays .080