SPS30 measurements nearly equal for PM10,PM4 and PM2.5

[box99h]

Hello,

I hope this is the right place to raise my question about measurements taken by the SPS30 sensor. The sensor is attached to a DNMS-T4.0+NodeMCU-V1.4 board and active for aprox. 48h.

To get a better picture of the issue if uploaded some data to here: First graph shows PM10, PM4, PM2.5 and PM1 measurements of SPS30. While the subsequent two compare PM10 and PM2.5 measurements of SPS30 and SDS011.

As can be seen from the graphs PM10, PM4.0 and PM2.5 concentration is nearly equal for the SPS30 measurements. While at the same time SDS011 measures significant different concentration.

Additionale somthing seems to happen around 4am (calibration / cleaning ?). Beyond 4am today there seems to be at least a minor difference in the values, but now the PM10 concentration is deviating from the SDS011 measurements which matched quite OK before.

Any ideas about this issue? Thank you.