BME688 cleaning protocol

[Christoforos]

Hello,

I am working the BME688 sensors on Sparkfun board 19096  and I have soldered my own PCBs with BME688 chip. I have been using the sensors for almost a year now following the burn in time (24-48 hours in clean air) before exposing to gases. I noticed some decline in their performance (reduced resistance range and sensitivity to VOCs). This is expected but my questions is how can we clean these sensors? Is ambient air in a room with windows open enough for 12 hours and the sensors operating in forced mode? Does pure Oxygen flow help? Could it be that the sensors age when exposed to high concentration VOCs for 24 hour sessions for 3-5 times? 

Thanks a lot!

[BSTRobin]

Hi Christoforos,

Do you place BME688 indoors? During your one year use of BME688, did you use IAQ or other outputs?

[Christoforos]

Hi BSTRobin,

I use the sensors indoors with the library BME68x on esp32 pico kit. I didn't use IAQ or BSEC library.

Thanks!

[BSTRobin]

Hi Christoforos,

BME688 does not specify the need for a clean snsor. If there is air flow around the sensor, the resistance value output by the sensor will change more significantly.
The sensor can not operate in low oxygen environment.
If you do not use the BSEC algorithm, you need to design your own algorithm and analyze the characteristics of the sensor values in different testing scenarios based on the resistance values output by the sensor.