Gravity I2C Oxygen Sensor SEN0322 calibration

userHead Matt.Slow 2025-01-22 01:37:38 641 Views0 Replies

Hi, 

I have issues calibrating my O2 sensor. It worked fine for some time, but after pressing the calibration button on PCB, the sensor shows correct value of approx. 20.9 in fresh air, but does not show lower concentrations correctly. E.g. if exposed to exhaled air, it now shows 18.3% instead of approx. 16% O2 as before. 

 

How can I change this? By writing different values to registers 0x08 or 0x09 I can change the offset, but is there also a way to change the slope? 

 

How to perform 2 point calibration correctly? 

 

Thanks in advance!