How do I verify whether the oxygen sensor is giving correct readings (performance proof)?

If you want to prove the performance of the last measurement, please verify the calibration values by inserting the sensor in the 'cal 0' and 'cal 100' calibration standards once you finished your measurement. If the device indicates 0 % air-saturation measuring the 'cal 0' standard and 100 % air-saturation measuring the `cal 100´ standard the sensor worked perfectly during the entire measurement.