Calibrating

Mini-OX does not directly measure the oxygen concentration but instead measures the partial pressure of oxygen within the measurement gas. In order to output an oxygen concentration (%) the sensor must be calibrated, or more specifically, re-referenced in a known gas concentration, typically fresh air.

 

Regular calibration removes the effects of application and atmospheric pressure changes and also eliminates any sensor drift that may occur during the first few hundred hours of operation.

 

Calibration, or re-referencing, is achieved by connecting the calibration input to GND and monitoring the status of the digital cycle output or by visually monitoring the on-board green LED. During the calibration process the output will either automatically calibrate to a fixed reference or can be manually calibrated to any output by way of a PCB mounted potentiometer.

 

NOTE:The fixed reference is factory set to 20.7% O₂ for calibration in fresh air,however this value may be altered for calibration with a reference gas of any known oxygen concentration. Any new calibration value will be stored on power loss.

 

The auto or manual calibrate function is user configurable; refer to Setting the Calibration Type and Measurement Range.

 

Output Variant	Recommended CalibrationPoints / Recommended Calibration Gas
0.1 - 25% O2	20.7% O2 / Fresh air
0.1 - 100% O2	100% O2 / Pure oxygen