Zero calibration

Zero calibration is together with air calibration one of the two steps of the POS calibration, see [MiPNet12.08]. It is done at closed chamber after all the oxygen has been removed by the addition of dithionite. A zero calibration is the last part of the sensor test and described in detail there. Unlike air calibration it is not necessary to perform a zero calibration each day.

A zero calibration should be performed

• from time to time as a record of instrumental performance: use the template [O2k-Calibration-list].

A zero calibration has to be performed

• when a new or serviced POS is used for the first time
• when a new membrane was applied to the sensor
• when the gain is changed
• when a new POS connector is used