How do I calibrate my O2NE+/ Safe-Ox+?


A full calibration check should be performed on the Ax O2NE+/ Safe-Ox+ after initial installation and every 18 months thereafter

In order to perform a calibration check, you will need the following equipment:

Test gas with 20.9% oxygen in nitrogen, ±2% tolerance

0.5 lpm regulator to suit the calibration gas bottle

Flow adaptor kit - Part No: P0120-651K

Then follow this procedure:

1. Remove the flow adaptor and gasket from its protective backing

2. Fit the flow adaptor including its gasket to the O2 sensor and connect, with tubing, to the cylinder and open the regulator to allow for the flow of gas over the sensor

3. Enter 'Technician Mode' by pressing the mode switch 3 times. If entered successfully the green LED will flash off for 1.5 seconds and on for 0.5 of a second

4. Select auto calibration by pressing the mode switch 4 times. The 2 Red Alarm LED's will light up to show you are now in this mode

5. Press the mode switch 2 times to start the Auto Calibration, the Red Alarm LED's will turn off and the Green LED will continue to flash

6. Wait one minute for the instrument to adjust. When the instrument has a new calibration value, the buzzer will sound one bleep and all the LED's will be off

7. Accept this new calibration value by pressing the mode switch 2 times. The green LED will flash to show the instrument has accepted the new oxygen value

To return to normal operation, press the mode switch once. The LED's and buzzer will illuminate/ sound 4 times before returning to normal operation

If during the one minute wait period, the red or yellow LED's are illuminated consult the table below:

ON OFF OFF Calibration gas is above allowable range Ensure the calibration gas is 20.9% oxygen in nitrogen with ±2% tolerance
OFF ON OFF Calibration gas is below allowable range

Ensure the calibration gas is 20.9% oxygen in nitrogen with ±2% tolerance

OFF OFF ON Internal fault Contact Analox

For a brief demonstration of the calibration process, please watch the video below:

O2NE - 4. Calibration from Analox on Vimeo.


Note: For best performance the monitor should be powered and allowed to warm-up for approximately 2 hours before calibration is performed. This will allow the whole instrument to stabilise at operating temperature.