I searched past messages, and see that generally mesh or screens are discouraged as affecting the airflow. But, recently I discovered that my PA II flex had been down for weeks because I did not know that one side was saturating at full scale. On taking it down, a relatively small spider came out, just a bit larger than an ant. I then carefully disassembled it, wiped and vacuumed other webs and dead bugs out. I think? it is back to working now, probably takes a week or two for the statistics to get back to normal. From 34% A/B comparison, I’m back up to 64% after about 10 hours (was always 100% before). I guess my graph will be a mess for a couple of weeks or more. So, a few questions:
Is it okay to vacuum through the holes in the laser particle sensors?
Is there a way to get an email or SMS notification if confidence % falls off in the sensor A/B comparisons?
Is there a way to clean up or delete the saturated data on the graph after a spider intrusion event?
I had a similar problem. My Purple Air sensor started giving crazy readings so I took it apart and cleaned the air channel openings (the fan and the opening near the connector) of the particle counters. That didn’t help, so I actually disassembled on of the particle counters. That isn’t easy because it’s clamped together by a stainless cover that’s hard to remove. [PA: How about selling spare covers?]. To my surprise I discovered a filament of spider web that had been spun across the beam path, right over the photodetector. So a small spider must have crawled through the airway, decided the beam path was a good place to spin a web and left! I then reassembled the particle counter and the PA sensor and to my great surprise it actually worked! So these devices are actually serviceable if you have the stomach for it. The bright spot to the right of the photodiode is the web before I removed it.
