Testing My El Cheapo Particle Meter

TLDR; El Cheapo has reasonable PM2.5 readings, and terrible PM10 readings.

I got a particle meter off eBay for $40 and as per being from China it is unbranded so I have no idea what to call it.

Observations

I have placed the meter on my air purifier and it recorded 1 PM2.5. This gives me confidence it has a reasonable zero point accuracy.


Secondly in testing the DIY purifier it has tracked the count dropping as you would expect, this makes me believe it has reasonable repeat-ability. If it didn't respond or jumped up and down I would have less confidence in it.

Comparing PM2.5 to Temtop

I borrowed a $300 particle meter from work, which given the price I'll assume is more accurate.

The El Cheapo did reasonably well as you can see in the scatter plot. I did find El Cheapo responded quickly to changes (like going outside) while Temptop took awhile to detect the new air. I believe this is due to El Cheapo having a fan.

On average the Temtop reported values 30% higher than El Cheapo.

Comparing PM10 to Temtop

El Cheapo was consistently under reporting PM10, and as such I will not trust its values. Of the values I observed it seems PM10 is around 150% of PM2.5 on Temtop, so I'll just assume that to be the case when I take my readings.