A Calibration Check, or Accuracy Check as it is sometimes known, is a test of your breath testing device’s ability to read a known alcohol standard within a certain tolerance. This is accomplished by running a standard with a known alcohol concentration through the instrument’s sampling system and verifying that the result is within an acceptable tolerance range of the expected value of the standard.
If the instrument does not produce a result within the tolerances required by your testing program, the instrument must be calibrated. Calibration is the adjustment of the analytical system so that it will read a known standard properly.
Refer to your program’s Quality Assurance Program for details.