Have noticed odd behavior with the HAM4 Dust Monitor (listed as #1). Have gotten MAJOR alarms for 0.3um particles (several hundred up to a few thousand counts!). Conversely, 0.5um particles has been virtually 0 for days. Mentioned high counts to Betsy before she went out to HAM4 today, and she mentioned that she only saw small counts out there on the floor. So there seems to be a discrepency some where.
Attached is a trend of the last 5-days. Will send an email to Jeff B.
This dust monitor looks to have fishy readings. Why are there lots of particle counts of 0.3um size but 0 counts on the 0.5um size? When I looked at the physical monitor a few times throughout the morning Friday, 0.3um always was reading ~10-30 counts, while 0.5um was reading 0. There must be some calibration diff between what reads on the actual monitor screen and what reads out in the control room trend data. Never-the-less, it's hard to think of how we could be dirty at 0.3 but not at 0.5.