Alco-Sensor IV Accuracy Check - Page 1

An accuracy check should be performed periodically. The frequency should be determined by your Quality Assurance Program.

Prior to running an Accuracy Check you should make certain that the Standard you will be using is current and all of the operating parameters for that device have been met:

  • Have as little tubing as possible between the gas out port of the standard and the mouthpiece of the Alco-Sensor IV.
  • Check Expiration Date (on Wet Bath Simulator Solution or Dry Gas Tank)
  • Check Temperature of the standard (Check Wet Bath Simulator Temperature)
  • Purge the simulator or dry gas regulator for several seconds
  • Know the current expected value of the Standard gas
  • If you keep a calibration log, it should be present

Tools Required: Before beginning have items available: instrument, calibration standard, new mouthpiece, calibration tool


  • Dry Gas Standard & Regulator
  • True-Cal or True Cal II Device
  • Alco-Sensor IV
  • New Mouthpiece
  • Calibration Tool


    Note: A calibration standard can be a: 
    • 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.