Frequently asked questions
1. Hardware and software
HOW CAN I BUILD ONE OF THE hackAIR SENSORS?
Check out the tutorials on the hackAIR website for full instructions and a list of materials.
DO I NEED TO KNOW HOW TO SOLDER?
Only the hackAIR mobile sensor requires a small amount of soldering. No worries: this is not hard, and a cheap soldering iron will work fine. You can find a great soldering tutorial from our friends at Adafruit.
IS THERE AN API?
Yes! Here is the link to the API documentation. You can see your own sensor measurements in raw format at this link: https://api.hackair.eu/hackair_data?access_key=1234 (replace 1234 with your access key)
WHICH CASE CAN I USE FOR MY SENSOR?
hackAIR recommends a plastic case in a bright colour with proper ventilation holes to keep the system cool. For outside use, make sure water cannot enter the case. The sensor should be placed 6-7 cm below the electronics, and its inlet and outlet should have free air flow. Read more
WHERE CAN I FIND THE SOURCE CODE?
All source code and a detailed documentation is on Github: https://github.com/hackair-project.
CAN I USE A DIFFERENT SENSOR TO THE SDS011?
Yes. Alternatives are: DFRobot PM2.5; PMS5003; PPD42NS (Grove). You can find instructions on how to incorporate them in the technical documentation.
CAN I USE ETHERNET INSTEAD OF WIFI?
Yes. Instructions for how to build a sensor with the Arduino Ethernet Shield are in the technical documentation.
WHAT’S HAPPENING WITH THE TEMPERATURE AND HUMIDITY MEASUREMENTS FROM MY hackAIR HOME V2?
The hackAIR home v2 comes with an optional temperature and humidity sensor. As low quality sensors are sensitive to high humidity and temperature changes, we are using a normalisation function on the sensor itself to adjust the air measurements in these situations. hackAIR does not transfer temperature and humidity measurements to its platform at this stage.
2. Understanding the data
WHICH POLLUTANTS DOES hackAIR MEASURE?
The sensor measures particulate matter, the most damaging air pollutant. Particulate matter are divided into groups according to size, yet all are invisible to the human eye. Larger particles (PM10) consists of substances such as dust, asbestos and lead, and can get into the lungs, while smaller ones (PM2.5) include organic compounds and metals, and can penetrate deeper into the respiratory system.
HOW DO YOU ESTIMATE AIR POLLUTION FROM PHOTOS?
The colour of the sky provides a reliable estimate of air pollution and particulate matter. The colour from the photograph is broken down into the percentages for its component colours red, green and blue, taking into account influences on those percentages such as the time of day (for instance sun brightness and position).
HOW ACCURATE IS THE SENSOR?
The SD011 sensor is the best sensor available at this price. However, its price also means that its results are not as accurate as professional air quality sensors. Its specifications say the maximum error is ±15% and ±10 µg/m3. Our test show the accuracy, in normal conditions, to be higher.
HOW DO YOU DETERMINE THE AIR QUALITY RATINGS (BAD, MEDIUM, GOOD)?
hackAIR deals with point measurements for particulate matter pollution from a variety of sources and in different units of measurements. As this can get very complicated, we use an internal index to be able to compare and display measurements consistently. On the platform, you will often see ratings like bad, medium, good. These ratings translate to actual measurements as follows:
|Rating||AOD scale (for image analysis)||PM10 scale (μg/m3)||PM2.5 scale (μg/m3)||Blobs detected (hackAIR cardboard)||hAQI index (from data fusion)|
|Very Good||>=0 and <=0,14||>=0 and <=20||>=0 and <=10||>=0 and <=1500||>=0 and <=1.5|
|Good||>0.14 and <=0,34||>20 and <=50||>10 and <=25||>1500 and <=2500||>1.5 and <=2.5|
|Medium||>0.34 and <=0,44||>50 and <=70||>25 and <=35||>2500 and <=3500||>2.5 and <=3.5|
3. Technical support
MY SENSOR ISN’T WORKING. WHO CAN HELP ME?
Please check the tutorials carefully, then review the technical documentation. To contact hackAIR, email us at email@example.com or tweet us @hack_air. We’ll do our best to get back to you within a few days.
WHAT DOES IT MEAN WHEN MY SENSOR SHOWS ‘NAN’ MEASUREMENTS?
If you are seeing a weird “nan” value when you access the hackAIR platform to check your measurements, this means that your sensor is not properly assembled and it cannot measure air pollution. First, make sure that the wires are at the right pins and fit well. If everything is at the right place, check if any of your wires are damaged and replace them. If you still cannot see any measurement, please contact us at firstname.lastname@example.org.
WHERE DO I UPLOAD A PHOTO OF THE SKY?
You will need the hackAIR mobile app to upload a photograph. Download it here. When taking a picture, please ensure that a good part of the photo contains the blue sky (not just clouds). The sun should not be visible in the picture, and the photo should not be taken near sunrise or sunset.
CAN PEOPLE FIND MY SENSOR AND WHERE I LIVE?
No. The hackAIR platform uses your username and no one will know whose sensor it is unless you use your real name. If you want to share your location, you can make your profile ‘public’ and share your location with the hackAIR community.
5. Suggestions & Contact
WHO DO I CONTACT WITH IDEAS AND SUGGESTIONS FOR HACKAIR?
We love to hear from you. You can send us an email at email@example.com or directly contact Panagiota Syropoulou, our project coordinator, directly at syropoulou.p [at] draxis.gr.
6. Air pollution
WHY IS PARTICULATE MATTER SO IMPORTANT?
Particulate matter is the air pollution most damaging to human health. 88% of the people living in cities around the world are exposed to levels that are considered damaging by the World Health Organization. It causes strokes, asthma and bronchitis, and heart disease that lead to 400.000 premature deaths, and 6.500.000 ill people per year in the EU . Smaller particulate matter (PM2.5) reduces life expectancy in the European Union by more than 8 months.
WHAT CAN I DO TO REDUCE AIR POLLUTION?
- Cycling, walking or public transport instead of taking the car is a good start.
- Pick an electricity supplier that provides renewable energy and/or avoids coal power, and reduce your use of electricity where feasible.
- Change your diet to reduce meat intake and eat more organic/ecological produce. Ammonia emissions from stables and the use of fertilizer contribute to air pollution.
- Vote for politicians and representatives that take air pollution seriously.
- Voice your concerns to institutions, and in planning and project consultations.
- Join, support or start an interest group that actively works for clean air.
HOW CAN I PROTECT MYSELF FROM PARTICLE POLLUTION?
If possible, stay away from its sources outdoors, such as main roads, construction sites, power plants, industry and airports, especially when they are at their peak of operations, and you exert yourself. Indoor, you may want to make sure you air the places where you have a toaster, burning candles, gas stove or laser printer. That being said, particulate matter is invisible and everywhere and it is therefore very hard to completely avoid the risk.