Particle Counters

[Blizzard]

The Dylos read-out is in thousands of particles per cubic foot, so how can you tell it's 1200 particles? I assumed you meant it read 1200, which would be 1200 thousands, no?

Doesn't the manual say "the numbers represent particles in .01 cubic foot of air"?

[LarrySabo]

Doesn't the manual say "the numbers represent particles in .01 cubic foot of air"?

Awk! I realized 10 minutes after making my post that my unit displays thousands of particles per cubic foot, whereas the units normally display hundreds of particles per cubic foot. So, Jared no doubt read 12 on his meter in unfiltered air, meaning 1200 particles per cubic foot.

The values are scaled so that these represent the concentration of particles in approximately .01 cubic foot of sampled air.

.... so a reading of 1 means 1 particle per hundredth-cubic-foot, which equals 100 particles per cubic foot -- Class 100.

Well, that purchase was a waste of money!

[Jared]

Actually, Larry, my meter was reading 1200 so I guess that's 120,000 particles per cu/ft of air in the open office space. But, that's reading in a carpeted room with acoustic ceiling tiles. I think the ceiling tiles are probably the biggest source of contamination. But, after my clean hood has run for a couple minutes, the Dylos stays pegged at 0 and 0 count. If I even see it hit 1 I'll wait longer before opening a drive. Most days it's only about 2 minutes of running to get there, but I've seen an odd day here and there where it was taking 20 or so minutes to get there. Probably something got into the hood and left a lot of dust in there.

Suffice to say, it's quite sensitive and I know right away if there's a problem. Mission accomplished.