For a complete list of all the Air Quality Sensors test on the World Air Quality Index project, check our sensor overview page.
The SDS 011 Sensor
The SDS 011 Sensor is a quite recent Air Quality Sensor developed by inovafit, a spin-off from the university of Jinan (in Shandong).
With its size, it is probably one of the best sensor in terms of accuracy: While other sensors tend to focus on shrinking the sensor size, the SDS 011 has opted for a size tradeoff allowing it to use a larger fan. And the larger the fan, the better the quality.
Specifications
This is the specification for the SDS011. One should not consider all those values for granted as there is quite often a big difference between what is said to be possible and what is actually possible (and this is why we are setting up all our experiments).
Output: PM2.5, PM10
Measuring Range: 0.0-999.9μg/m3
Input Voltage:5V
Maximum Current: 100mA
Sleep Current:2mA
Response Time1 second
Serial Data Output Frequency: 1 time/second
Particle Diameter Resolution:≤0.3μm
Relative Error:10%
Temperature Range:-20~50°C
Physical Size: 71mm*70mm*23mm
Inside look at the sensor
The clever engineering in the SD011 is to use the PCB as one side of the casing (allowing to reduce the BOM cost). The diode is mounted on the PCB side (this is mandatory as any noise between the doide and the LNA should be avoided). The laser mounted on the plastic box and connected to the PCB via flying wire.
The biggest problem of this design is that the entire sensor inside is getting very dusty, as shown on the picture below after running 24/7 for more than 6 months. This is actually not so bad since the dust did not get accumulated on the diode, nor on the laser frontend. As concern the fan, dust accumulation is a "normal behavior" also seen on the dylos.
Last, as concerns the PCB, is it quite simple. The main CPU is an 8bit processor (scratched to prevent from beeing reversed engineered!). Under the shielding one can find the Low Noise Amplifier (directly mounted on the opposite side of the diode).
Experiment Setup
There are two SDS011 colocated. The SDS011i #1 is a sensor which has been used outdoor for several months. The SDS011 #2 is a brand new sensor (from Sept. 2016).
Real-time data
Current BAM readings are:
PM2.5 mass in mg/m3 -,
updated on -- (China time).
First SDS011i #1 (old) readings are:
PM2.5 mass in mg/m3 -,
PM10 mass in mg/m3 -,
updated on -- (China time).
Second SDS011i #2 (new) readings are:
PM2.5 mass in mg/m3 -,
PM10 mass in mg/m3 -,
updated on -- (China time).
Comparison with Official BAM readings
PM2.5 based Air quality data:
PM10 based Air quality data:
--
For the list of all air quality sensors, check the Sensor Overview page
Read or publish comments (they rely on Disqus)
About the Air Quality and Pollution Measurement:
About the Air Quality Levels
AQI
Air Pollution Level
Health Implications
Cautionary Statement (for PM2.5)
0 - 50
Good
Air quality is considered satisfactory, and air pollution poses little or no risk
None
51 -100
Moderate
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
101-150
Unhealthy for Sensitive Groups
Members of sensitive groups may experience health effects. The general public is not likely to be affected.
Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
151-200
Unhealthy
Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects
Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion
201-300
Very Unhealthy
Health warnings of emergency conditions. The entire population is more likely to be affected.
Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
300+
Hazardous
Health alert: everyone may experience more serious health effects
For very useful health advices of Beijing Doctor Richard Saint Cyr MD, check www.myhealthbeijing.com blog.
Usage Notice: All the Air Quality data are unvalidated at the time of publication, and due to quality assurance these data may be amended, without notice, at any time. The World Air Quality Index project has exercised all reasonable skill and care in compiling the contents of this information and under no circumstances will the World Air Quality Index project team or its agents be liable in contract, tort or otherwise for any loss, injury or damage arising directly or indirectly from the supply of this data.
