27-04-2021, 20:19
(27-04-2021, 06:37)tobyportugal Wrote: I will mount another SDS011 without a t° sensor to understand its correction (if correction is made).
Another SDS011 with a t° sensor in a normalized shelter to measure the quality of its correction.
I don't know to which system you will connect your SDS011, nor the software it uses, however from the following document, things are clear.
MASS CALIBRATION AND RELATIVE HUMIDITY COMPENSATION REQUIREMENTS FOR OPTICAL PORTABLE PARTICULATE MATTER MONITORS
Some DIY systems doesn't apply any correction on the software, that is why, specially on sensors installed in rural zones, you can see substantial changes on the readings along a day / night.
As in the case, observed on first post (regarding CO2 readings), without correction, the changes on the PM readings are in many cases caused by the natural changes of %RH along the day / night.
In the case of the WeatherDuino AQM, the software was designed in a way, that without the readings from the T / H sensor the system will not work properly. In other words, installing the T / H sensor is mandatory.