SDS sensor gives (to) small output

1

I have two sensor kits (1 in the frontgarden and 1 in the backgarden). Until the begin of this month (01-05-2021) both works fine. Only from the first of this month the sensor in the frontgarden (near the street) only gives values between 0.3 and 0.01 µg/m³ for both PM2.5 and PM10. Before it was between 5 and 15 with normal weather. So I think there is something wrong with the sensor.

What i already tryed;

  • restart the sensor
  • reasamble the sensor
  • run the sensor out of the casing (a cablebox)
  • reflashed the NodeMCU

The debug log don’t show anything I can anything with.

Starting Webserver... 192.168.0.17

ChipId: 12932457

MAC Id: e8db84c55569
Read SDS...: 18-11-16(1f62)
Stopping SDS011...
Read DHT...
Send to :
sensor.community
Madavi.de
custom influx DB
----
Auto-Update active...
ws: ws: debug level ...
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
R/ SDS011
PM10 (sec.) : 0.10
PM2.5 (sec.): 0.10
/R SDS011
PM10:  0.10
PM2.5: 0.10
----
## Sending to sensor.community - SDS011
Succeeded - api.sensor.community
R/ DHT22
Temperature (°C): 20.30
Humidity (%): 64.20
----
/R DHT22
## Sending to sensor.community - DHT22
Succeeded - api.sensor.community
## SendinR/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
R/ SDS011
PM10 (sec.) : 0.00
PM2.5 (sec.): 0.00
/R SDS011
PM10:  0.00
PM2.5: 0.00
----
## Sending to sensor.community - SDS011
Succeeded - api.sensor.community
R/ DHT22
Temperature (°C): 20.00
Humidity (%): 61.80
----
/R DHT22
## Sending to sensor.community -

have someone of the members here a idea to see what the problem is or what the problem can be??

Thanks already for the time

Jelmer (the Netherlands)

2

I have never seen such logs. Does the fan of the sensor start every 145 seconds ? Is there a red light on the sensor ?
If the connections are well done (on the good pins), i would say that the SDS011 is no in a good condition. Have you ever shortcut it while connecting the pins ?
Or maybe it is just some bade cables…

3

Thanks for the response.
The fan start spinning every 145 sec. Also the red flash is there on the sensor.
The cables are correct connected, until 10 days ago the sensor had been working properly for about a 3 months.

I will try and swap the sensor with the one in my backgarden. To see if it make sense with the response. I’m almost thinking the same as you that the sensor is bad/broken.

4

Swapping the sensors is a good idea but afterwards try looking at the diode with a mobile phone - it will show the ‘light’ you can not see. Otherwise check for obstructions and INSECTS! Good luck.

5

Thx for the idea. I had also had soft sucking and blowning in to the tube (with the idea of dust and insects) but did not change anything. It also did not measure my breath.

I have swapped the sensors a couple of days ago and as aspected now the backgarden don’t give a normal output.
I have ordered a new sensor and placed this one. And now both the devices gives a normal output.