Neph Bin Sizes and Final Data Calculation

Hi, I was wondering if the size ranges for the 6 neph bins (neph_bin0 through neph_bin5) are accessible somewhere on the Quant-AQ website. Additionally, I was curious as to how the data from the nephelometer and OPC are reconciled to end up with the final PM1, PM2.5, and PM10 data.

Hi Olivia,

The size ranges for the bins are documented here, though the nephelometer cannot size resolve particles based on size and thus the numbers are pure calculation. As far as how the data are reconciled, have you seen our technical note here?

The technical note is very helpful, thank you!

If I can just add one question. How is stitching happening, I mean is just a simple addition of PM (less than 1um) from nephelometer + PM (above 1um) from OPC? Also, how are you calculating only PM1 from Neph because Neph is giving mass for full spectrum, is it linear division or something else? I tried to read through the technical notes and your 2020 paper with Prof. Jesse Kroll (which was super helpful) but couldn’t understand/find it there.

Hi Shivang,

Unfortunately, we cannot disclose exactly how it is happening, as that is our IP. The nephelometer we use (PMS5003) only measures sub-micron aerosol and the rest of the values are pure estimation. For more info on that, please see the papers by John Volckens and others.

Hi David,
I am sorry, I understand. I will read the literature to understand the concepts better. Thank you for answering promptly. Appreciate it.