Build a low-tech air quality sensor
Cardboard offers a crude measurement. Estimates of air pollution by particulate matter are therefore only given at three levels: low, medium and high.
What you need
- A clean, dry, empty drinks carton (e.g. Tetrapak)
- Some petroleum jelly (e.g. Vaseline)
- Some household string
- Some tape
- A counter weight (e.g. a battery, coin, paper clips)
- A macro lens for your smartphone
Macro lenses can be found online. The Blips Micro, for example, is excellent and costs 13,90 EUR.
- A pair of scissors
- A pencil
- A buttering knife
- A mobile macro lens of x6 or greater magnification
Assemble the sensor
- Cut out a 1x1cm area around the two dots in the middle and place it flat on a well-lit table. Be careful not to touch the surface of the cardboard sensor.
- Attach your macro lens (e.g. Blips micro) to your cell phone’s camera.
- Open the hackAIR app and go to Photo > Take a photo of your hackAIR cardboard sensor.
- Locate the two dots on the test surface with your cellphone’s camera. Focus on one of the two dots until you can see the shape of the dot as clearly as possible through the camera.
- Take the picture and upload it to the hackAIR app.
- You will immediately receive an estimate of the air quality.
If you run into problems or have questions, check out the hackAIR FAQ.