The SDS011 sensors have been in use for more than 2 years now. Do these sensors require maintenance ? and if so, how ?
Or are they simply worthless after a certain time ?
When comparing the data at the 3 locations, I have doubts whether the output values are really correct (of course a certain tolerance I do understand
And another question, at the particle sensor, where the hose is connected, is that the air input or the output ?
The pipe is attached to the inlet. The exhaust is the opening in the black casing attached to the larger silver/chrome casing. Mine are running for a few years, still giving excellent results. But I remember I got strange results now and then and cleaned the pipes (spiders!). I also opened one and cleaned it. But even after several years they are still in very good agreement with a nearby official station.
Your sensor looks so new!
On the ones that have run a couple of years that I’ve seen, the shield plate around the electronics is usually complete covered in a brown rust layer. Also there’s usually some dirt in the plastic tubing.
I personally don’t have any data on reliability vs time.
The datasheet has a recommended installation direction, with the plastic tube coming in either from the side or from the top, so that’s at least different from your situation.