TZOA Wearable Air Quality Tracker

One of my basic tools for measuring air quality is TZOA, still it is under development but it is getting better every day.

TZOA measures basically fine particles such as PM10 and PM2.5 among other stuff like UV/Light exposure and temperature/humidity levels.

As a wearable device it allows you to carry it everywhere for example work place, gym, home, car etc, so it will allow me to document my everyday exposure into air pollutants and take active actions.

I will talk more about it in my following posts, so as always stay tuned.


PM2.5 Device Comparison

There are so many devices available right now on the market that measure PM2.5 (as we can see on this post) but there aren’t all of them the same. In my opinion PM2.5 is the key for air quality monitoring. Different sensors, different manufacturers and also different software can give different results.

Let’s try to analyze them and see which of them are accurate and which ones aren’t. In order to do that firslty I will present some the sensor manufactures and models. Prices are in USD:

  • Novafitness SD011 ∼23$
  • Plantower PMS1003 ∼17$
  • Plantower PMS3003 ∼17$
  • Shinyei PPD42NS Made in Japan ∼10$ (R² ∼.83)
  • Shinyei PPD60PV (More expensive than the PPD42 because it allows smaller particle detection) Used by AirBeam
  • Samyoung DSM501 Korean copy of the Shinyei PPD42 ∼5$ Used by Speck
  • Sharp GP2Y10 ∼15$ (Used by Awair and probably by Foobot) (R² ∼.74)
  • TZOA RD02  135$-600$ Used by TZOA Wearable (R² .9253)
  • Dylos DC1100 ∼300$ (R² ∼.85)
  • DustTrak TSI DRX 8533 ∼3000$ (R² ∼.97)
  • Turnkey Instruments Dustmate ∼3200$

Here we can see some graphs of different sensors cheap ones and expensive ones. In general the expensive ones are more accuarte and industrial graded but some new companies have managed to build low cost sensors with high accuracy.


Screen Shot 2016-01-29 at 22.49.01
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Shinyei R-squared .83 correlation value
Screen Shot 2016-01-30 at 19.12.59
Sharp R-squared .74 correlation value
TZOA R-squared .9253 correlation value


On the table below there are some of the devices that measure PM2.5 among other stuff and have been reviewed by the Air Quality Sensor Performace Evaluation Center aka AQ-SPEC Focus on the R² (correlation) values on the last column “Sensors vs FRM/FEM Method”.

An R2 of 1 indicates that the regression line perfectly fits the data, while an R2 of 0 indicates that the line does not fit the data at all. So, closer to 1 then better results.




Low cost air pollution sensors: New perspectives for the measurement of individual exposure? Madelin Malika, Duché Sarah

The Air in Greece

Winter holidays are here and after a long time I am back in Greece to spend them with my family. Unfortunately the crisis has affected the air quality here too.

Fireplaces: Huge problem because most houses choose them as a heating source, so they burn wood nowadays. Previously they were burning oil but its price climbed up and people tured to wood. PMs inside houses are on high values 20-40μg/m3. The threshold is below 25μg/m3. Outside values are high too with similar values of 18-38μg/m3.

Smoking: One more time Greek people disappointed me with the way they decide to behave in interior places. They smoke everywhere like in cafes, in restaurants etc. There is a law that prohibits that but they don’t follow it at all. How can we make people understand that this is a toxic air? It isn’t about them only but for all the people around them that they choose not to smoke like non smokers and kids. They are so proud smoking inside. Socialy is still something cool in Greece I guess. I asked some friends what will happen if I raise my voice. Will I find justice or will they throw me outside the places? Sadly the answer was that probably they will think I am crazy.

Car’s Exhaust Pipe
Cars: Yes there was a big scandal about some automobile companies that made-make car that pollute air beyond any consideration but that hasn’t affect how people think and move. People love Cars and traffic apperantly too.

Agricultural Fires
Agricultural Fires: Through my trip from Sterea Ellada to Peloponeso farmers all over the countryside were burning unwanted material, from plastic to wood. I was hopping to breathe some pure air but that wasn’t the case on that trip. I know that there is a law that prohibits that action but I guess people don’t care.

If you are aware about air quality, a wearable device like TZOA is absolutely necessary in case you want to find places with good air quality in Greece or on the rest of the planet Earth.

My Air Experiments


I know that I have promised you all that I will conduct some experiments but so far I haven’t received my devices. (Sad face!)

Both of them are delayed, even big companies like Apple sometimes have issues during productions so for example Awair told me that the devices are in final process of manufacturing and they will begin shipping in a month. TZOA from the other hand is a lot closer to their initial timeline to deliver their device.

As always stay tuned.

Awair indoor Air Monitor

UnknownAwair monitors indoor air, gives solutions when air quality turns unhealthy and communicates with other smart home devices so you can stay healthy.
Apart from the beautiful design, Awair’s sensors monitor the six most important factors of indoor air quality & well-being.

  1. Temperature:  -40 to +125°C / -40 to +257°F
  2. Humidity: 0 to 95%
  3. CO2: 0 to 4000 ppm
  4. VOCs: Air Hydrogen, Hydrogen Sulfide, Ammonia, Ethanol, Toluene to name a few, ranging b/w 0.1~30 ppm
  5. Dust: Particles PM2.5 from 0 to 500 μg/m3. (On their site they mention, dusts and particles under 2.5mmg)
  6. Ambient light

Awair is one of the tools I will use to monitor my indoor air quality (TZOA is the other one). It has awesome design and I love the walnut timber, high quality of course and is painted without harmful VOCs. It will constantly show me the AQI inside my bedroom which is the most important room in my home. During day we are more aware about air quality but during night we aren’t, so I will be able to see if my bedroom offers me more than a bed and a regular night sleep. During sleep our bodies rebuild and our minds refresh, so do we offer them the best conditions?

During day and night time I will conduct experiments with it. Measuring CO2 with and without plants, VOCs with different cleaning products plus furnitures and dust particles from mattresses and bed clothing. All of these experiments will be published here on #SeetheAir.

Temperature and humidity sensors are very import inside a room for many reasons as well. First by knowing the temperature inside a room you can have optimum sleep during night time, in general is recommended slightly cool temp 65ºF/18.5ºC. Second low humidity may cause respiratory problems, itchy eyes and skin. On the other hand, high humidity will result in molds that serve as breeding ground for bacteria. Also dust mites love high humidity. The optimum humidity level is 35-45%.

I live on the coast and humidity levels are so high here so I had to invest on a dehumidifier but I did a smart purchase because I bought an A/C with dehumidifier, this way I control temperature and humidity. Awair is capable of communicating with smart home appliances and turn them on/off via IFTTT. In case your home appliances aren’t smart enough you can boost them with TADO The Smart A/C Control.

Finally the app is elegant and simple for the everyday use but with valuable infos.