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. 

[Jet]

Hi Sir:

    BVOC is same as TVOC, when BME680 is used to measure indoor air qualilty, it is BVOC; when BME680 is used to measure outdoor air qualilty, it can be said TVOC.

    BME680 can output the bVOC value in ppm. But it is not recommended to convert this value from ppm to mg/m3, because this value only estimates breath-VOC concertration to indicate current VOC level (derived form bVOC lab test) no accuracy specified

[terence06]

Thanks for your reply. So how can I know the bVOC (or TVOC) result is good or bad? Because I saw that most of the website/application use TVOC in mg/m3 and use this value to classifiy whether is good or bad. 

So if we get the bVOC value from BME680 (in ppm), then any table or reference information can help us to classify the good or bad condition? 

Thanks

[Jet]

Hi Sir:

   You also can use this value to classifiy whether is good or bad, like other most of the website/application use TVOC in mg/m3.

    But because this value is the transition value based on the laboratory data, the accuracy is unkown and uncertain.

    Of course, you can transfer this value to mg/m3 and know the air quality worse or better compared with the previous time.

[terence06]

Hi, thanks for your fast reply. Then can you let me know how to transfer ppm to mg/m3? We only miss this step and can settle down whole product development. Thanks