This post is also available in: Spanish
In practice, it consist on three aluminium cylinders with similar dimensions of a soda can (45x45x155 mm the biggest one) as the ones at right, that I placed in different points of the house and with which I can get these measurements:
- room and outdoor temperature in ranges between -40 to 65°C, with a +/- 0.3°C accuracy;
- humidity from 0 to 100% with a +/-3% accuracy;
- barometric pressure in ranges between 260 to 1160 mbar, with a +/-1 mbar accuracy;
- carbon dioxide concentration in a range between 0 to 5000 ppm (parts per million) with a +/- 50 ppm or +/-5% accuracy;
- noise in a range between 35 dB to 110 dB;
- air quality index taking into account the most important pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (no2), ozone (o3), carbon monoxide (co) and sulphur dioxide (so2). These data are not measured by the station itself but it receives them from the european project CITEAIR (Common Information to European Air).
The station also displays the weather forecast issued by MeteoGroup.
I can access all this information whenever and wherever I am with an Internet connection or cellular data coverage, through an interface looking like this:
Grading: Medio-high performance
If I´d had to grade the station 0 to 10, it could be close to 8 taking into account the following factors, which are the station´s most useful features for me:
- Design: 10;
- Performance: 10;
- CO2 sensor calibration: 3;
- Measurement accuracy: 6;
- Interface: 10;
- Support and software updates: 8;
Carbon dioxide sensor calibration
A medium-high grade is not bad, but one of the key station´s features which persuade me was the CO2 measurement. You will notice that this is one of the aspects to assess and fails clearly: 3.
The CO2 sensor calibration system lacks, directly, technical solvency. The optical sensor measuring CO2 calibrates considering that the lowest CO2 level all around the globe is 400 ppm, regardless of the location. This is incorrect.
I made contact NetAtmo staff to clarify this point. They treated very correctly my request but they finally recognized that the station meets technical constraints impeding a CO2 calibration according to the real CO2 level in every location and that the only technical possibility was to establish the most representative value available, the data measured at Mauna Loa Island in Hawaii.
So, regardless the place where the station is installed, the sensor will calibrate considering that the minimum CO2 level is 400 ppm, being this value much more higher in many locations along the globe.
The less bad news is, despite my village´s air may be more polluted than an island in the Pacific Ocean, air quality is good. When the CO2 sensor calibrates, his default value 400ppm won’t be very different to the real value. It may be useful for me.
Other factor decreasing the station´s overall grading is the measurement accuracy, 6. The temperature sensor in one of the modules displays values exceeding the accuracy range +/- 0.3°C. Maybe two degrees.
I´d get it again
Despite the untrustworthy calibration system of the CO2 sensor and the deviation in the values in one of the temperature sensors, the station is fantastic. The interface to check the information is delight: functional, estable, fast and pleasant.
The station got several awards, very well-deserved
This is not the kind of device I´d trust if I´d had to go to Chernobyl and it´d measure atomic radiation, but this is perfect to know the weather as a citizen.