09-15-2022 09:29 PM
I'm using the BME688 and my goal is to achieve accurate, stable, calibratable readings of certain VOCs, at the level of single to tens of PPM. I need a reading every 15 minutes or so that will be accurate and I'm having issues removing the baseline drift from my readings. I've tried the raw gas resistance readings, air quality index, and bVOC and none of them are both stable and accurate enough to give me the readings I'm looking for. Does anyone have any ideas or preferably examples of removing the baseline drift for PPM VOC readings?
09-19-2022 03:59 PM
Hi CIDJP,
For your feedback, do you use BSEC or your own algorithm?
09-21-2022 08:16 PM
I've tried to collect data with the BSEC software and I've just looked at the raw data. I've tried calibrating a 0 and measuring the response from 2, 5, and 10 ppm samples. I've found that the baseline drift for the gas resistance reading is large enough that the response from gasses will be smaller than the change in baseline in a matter of a few minutes. When I try to measure with something like bVOC or IAQ, the response from the analyte is filtered out when it removes the noise.
10-21-2022 10:53 AM
Hi CIDJP,
You could run BSEC and wait until accuracy reachs to 3, then read output data from BSEC.