1
I were comparing a couple of PM2.5 monitor, in this case one Dylos DC1700, one Dylos DC1100 Pro and one Arivisual/IQAir
1
The diode and photocell was accumulated dust
2
I noticed that after 6 months of operation, the DC1100 was showing lower numbers comparing to DC1700, which was about a month in operation. So I check it out. On the back, looking through the fan, I could see one of the problems
3
and sure enough, after opening the case, dust was noticeable several corner
4
the exhaust fan was coated with a thick layer of dust
5
The diode and photocell was accumulated dust
6
a close up on the photocell