So, just got my outdoor sensor hooked up and the PM0.3 seems very high compared to the indoor sensors.
My downstairs indoor sensor is reading about 45, the outdoor sensor is fluctuating around 300… the windows have been open for about 2 hours and there is a nice airflow in the house…
Maybe my PM sensor is defective? The other readings seem normal. Sensor sticker says “PMS5003T-2023032701334”
PM03 is the particle count. It is not comparable to the PM2.5 that is measured in ug/m3.
As I can see, many people are experiencing this problem (PM 0.3 values from outdoor unit much more than from indoor unit).
Also described here: PM 0.3 accuracy / calibration
In my case the values are nearly 10 times higher from outdoor unit than from indoor unit standing near each other in the same room.
Which of them is right (if either) - do not know.
According to Plantower the PM0.3 count is a non calibrated figure and varies between batches of monitors.
We primarily make it available to show more fine grained details, especially in low concentrations but it should not be used as comparison between different monitors or batches.
Did I understand correctly: one should just ignore PM0.3 values as it really shows nothing meaningfull (some non calibrated value, different in different sensors batches)?
@Achim_AirGradient It would be nice to have some sort of documentation (may be a blog post?) with short description of all data one can see from the units (both indoor and outdoor):
CO2
Both indoor and Open Air units get values from Senseair S8 (Senseair S88 in new units).
Values are rather accurate (link?). With auto calibration, no correction needed.
Temperature and humidity.
Indoor unit: values are from Sensirion SHT40. The values are quite accurate, no correction applied.
Open Air unit: values are from Plantower PMS5003T. Raw values are not accurate, correction is applied. After correction temperature is rather good, humidity is still questionable.
VOC and NOx
Both indoor and Open Air units get values from Sensirion SGP41.
Index and RAW values are available. Read more about these values here.
PM
Indoor unit: values are from Plantower PMS5003.
Open Air unit: values are from Plantower PMS5003T.
PM2.5: correction is applied to make values more accurate.
PM0.3: non calibrated values varying between batches of monitors (nearly no practical usage).
… (others)