BME680 VOC ppm to mg/m3

[terence06]

Hi Sir/Madam,

I have a project is using the BME680 to detect the VOC value. BME680 which can output the bVOC value in ppm. Is it possible can convert this value from ppm to mg/m3? Also, is it bVOC is same as TVOC? 

Looking forward anyone can reply. Thanks a lot. 

[terence06]

Hi, thanks for your help to forward my question internal. We are looking forward your expert's contact and NDA.

[Jet]

Hi Sir:

     Please see the following comments:

     there are online converters which can do this, e.g. We also use this one as reference:
    https://www.unternehmensberatung-babel.de/berechnungen/umrechnung-ppm.php

   If you convert bvoc from PPM to mg/m3, you need to assume the current pressure, temperature and the molar mass of bVOC. The contained gases are mentioned in the BME680 datasheet in table 5 on page 10. By taking each single molecule weight and multiplying it with its content (e.g. 0.1 for 10%), you get the average molecular weight of bVOC.

    Hopefully, it can help you.

[terence06]

Hi Jet,

Thanks for your information. About the "multiplying it with its content (e.g. 0.1 for 10%)" , 10% is it mean the production tolerance?

[Jet]

Hi Sir:

    Correct, you can use it.

[terence06]

Hi,

Now we are using IAQ index as the VOC index for our product because Bosch IAQ index is directly related to VOC.

But may I know that is it "Isoflurane and Sevoflurane " can be detected by BME680? We search that they are anaesthetic gases used in operating rooms. We found that in the attached document for VOCS, these 2 anaesthetic agents are listed on page 3 under oxygenated compounds which is belong to VOC compound. Please advise. Thanks