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Interpreting Dylos 1100-pro readout questions
I can't decide if I should get a hotel room tohight or stay home. I _think_ I can stay home.
I did find this article online: https://aqicn.org/experiments/what-i...lly-measuring/
And I read Bill Pentz' page: https://billpentz.com/woodworking/cyclone/dylos.php
I think that means my PM2.5 count ( I prefer to work in micrograms per cubic meter if that is all right with you) is 1.05 or maybe 1.3 and my PM10 count is about 0.26? Yes? No? I am not very smart. I think I have pretty clean air. This is at the side table next to my recliner chair in the same room as my wood stove loaded about 15 minutes before.
Pic one is the Dylos readout, the second is an EPA funded outdoor airquality array about 4 miles from my house.
Thanks
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How to compare the readings
Both the Dylos and the Plantower (manufacturer of the sensor) are particle counters and it's appropriate to compare the particle counts, especially since the Dylos counter doesn't provide PM estimates.
The Plantower sensor bins the counts into six separate ranges, the Dylos into two. Fortunately two of the Plantower bins are the same as the Dylos, >.5 and > 2.5 so we can compare those. One problem is that the Dylos reads in Imperial units while the Plantower is metric. To convert, simply multiply the Plantower readings by 2.8.
Using the numbers in the image below you would compare 2.8 x 3490 = 9772 and 2.8 x61 = 171 to the two Dylos numbers. Agreement within about 20 or 30 percent I would consider good. Looking forward to the data!
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PM values versus particle counts
A particle counter displays it's measurements as number of particles GREATER in size than the reference value. So, for example, if the 2.5µm channel on the Dylos reads 26, that indicates 26 particles in .01 ft³ that are larger than 2.5 µm. It does not mean 26 particles of 2.5 µm size as there are really none that exact size.
A PM value indicates the total mass per cubic meter of particles LESS THAN the indicated size. So, for example, a PM2.5 of 35 means the total amount of material smaller than 2.5 µm is 35 gram per cubic meter.
PM values are cumulative upwards, like stalagmites. PM10 > PM2.5 > PM 1.0. PM10 includes PM2.5 which includes PM1.0 Counts are cumulative downward, like stalactites. (N>10) < (N>2.5) < (N>1.0) etc. N>1.0 includes N>2.5 which also includes N>10.
You're never measuring particles of a certain size. It's either particles greater than or less than that size.