Over the last few days I’ve noticed some gaps in the recording of particulates in the air using my air quality sensor.
The sensor is set to automatically measure and upload the following measures every 2 minutes:
- Temperature
- Air pressure
- Humidity
- PM 2.5 particulates
- PM 10 particulates
The recording of air temperature, humidity, and air pressure has been working without a problem, but the recording of air quality has been randomly stopping for the last few weeks. The PM2.5 and PM10 values are measured using an SDS011 fine dust sensor, which has a small fan that sucks in a sample of air, and a laser that measures the particulates in the air.
The SDS011 sensor has failed on me in the past. Near the start of the year it stopped working altogether, and I had a 2-month gap in air quality monitoring while I waited for a new sensor to be shipped from China. And it now looks – some 6 months on – that the replacement SDS011 is beginning to fail.
If I power-cycle the whole sensor then the SDS011 comes back to life and captures readings, but then after a few hours or days it just stops working again.
I suppose I should order a new one, just to be on the safe side. They’re not too expensive – about €20 on Ali Express, or about €40 on Amazon – but orders on Ali Express take ages to arrive.
There’s a mechanical element to the SDS011 sensor, as it runs a fan every time it takes an air sample. And I guess those mechanical elements fail over time.
I ended up ordering a couple of spares of this sensor from Ali Express – and was thankful that I had those spares a week or so ago, because another one failed, and I was able to swap it out straight away.