Ce capteur est une merveille.Avec un affichage e-ink, le capteur consomme très peu.L’app permet d’avoir un historique des mesures et permet de régler certains paramètres comme la fréquence des mesures.

L'appareil et l’application sont simples et font très bien ce pourquoi ils existent. L'application est optionnelle, pas de compte requis, pas de pub ou que sais-je comme certains objets connectés.Les mesures réagissent au moindre événement qui affecte l'air dans mon logement avec précision. A voir sur la durée.

I love the e-ink screen, the battery life, and the measurements are very accurate. It's a nice touch that you can connect your phone via Bluetooth and look at graphs of the data. It's definitely not cheap but you get a quality device for the price.

El mejor sensor de CO2 DEL MERCADO CON DIFERENCIA.

This CO2 monitor -- the product of Latvian engineering -- is one of the most awesome gadgets I have ever purchased. It's extremely accurate, unlike other cheap CO2 monitors on Amazon. It syncs with your phone using Bluetooth, so you can see CO2 levels over time (this is a killer feature that other monitors don't have). The e-paper display is incredibly clear. The batteries last for many months. It's very compact -- easily fits in a pocket.It's super interesting to analyze CO2 levels as you move into different spaces, e.g. when you board a plane, when the plain is airborne, etc., since CO2 concentration is a proxy for COVID risk. I was on an old Embraer jet, probably 30 years old, and the CO2 levels hit the highest level I have ever seen, 3550ppm! (The outdoor level is about 450ppm.)Also, not many people know this but you can measure cognitive decline starting at about 900ppm of CO2 -- and many apartments, especially new constructions, get way over this level. See the paper "Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments", Allen et al., Environmental Health Perspectives, for some shocking numbers about this.Once you start frequently monitoring CO2 levels, closing the biofeedback loop, two things happen: (1) you develop a new 6th sense -- you can start to predict the exact CO2 level just by how the air feels when you breathe it in. I can often guess the CO2 level to within 50ppm, without looking at the Aranet4. Weird and pretty cool. (2) You start to get really conscious just how stuffy the air is, and how much your cognitive function slows, even when the CO2 levels are high.

The aranet4 is such an excellent monitor, and really is the best bang for your buck in an accurate and easy to use monitor. We have used this in all the rooms of our home to measure air flow and how quickly C02 builds up - especially useful in the kitchen during various cooking processes and in the bedrooms overnight - but we have also brought it to work to measure the C02 and get an idea of the air flow in various offices as well. It's easy to set up, the battery life is excellent, and it's easy to bring with you anywhere. The app works well and is likewise a quick and easy setup. We keep this monitor in the main living area of our house and it's every easy to monitor when the C02 is accumulating and we need to crack a window or turn on an exhaust fan. It's been illuminating. This item is also very accurate, and more so than others and cheaper version. Totally worth the money and a reliable, trustworthy device for monitoring a really important aspect of our health.

Es fácil de usar y muy preciso.

I've owned several CO2 sensors. In particular, I've had 2 Awair Glow units, 1 first-generation Awair unit, 1 second-generation Awair unit, and a TIM10 CO2 sensor. Of these sensors, the TIM10 is my "gold standard" sensor, but it has the very, very annoying property of requiring AC power. Aranet4 promised to be a battery-powered CO2 sensor that could output data to an app. It delivers, but it requires calibration out-of-the-box, in my opinion.Measured against known good sensors (particularly my TIM10), my Aranet4 sensor read about 75ppm higher than the environmental level out-of-the-box. The app warns you that performing calibration will permanently erase the factory calibration data, which is somewhat scary, but I did it anyway. In order to validate that the calibration was successful, I had my trusted TIM10 sensor outdoors, connected to AC power, out of the sun, with the Aranet4 directly next to it, on a substantially windy day with extremely good air quality (as measured by PM2.5 and PM10 presence from AirNow and Purple Air). The floor, outdoors, in this configuration, as read by the TIM10 unit, was 380ppm of CO2. Before calibration, in the same environment, Aranet4 reported 480ppm. After calibration, Aranet4 reported within 15ppm of TIM10, which I considered a success, particularly given the rarity of having such a low reading. All of the Awair units bottom out at 400ppm.Following calibration, for the last few weeks, I've kept an eye on Aranet4 and TIM10 when they've been in the same room. There's approximately a 10-15ppm disagreement between TIM10 and Aranet4, which I consider a very acceptable deviation given that Aranet4 is battery powered, and TIM10 is AC powered.On the app side, Aranet4 provides a serviceable iOS app. The iOS app itself is perfunctory. It provides graphing, exporting data (as csv, including CO2, pressure, humidity, temperature, and date of sample), and basic reporting features. It doesn't support dark mode, though, as an example of its perfunctory nature. The app developers didn't consider the performance impacts that storing all of the data would have on the graphing component, though, so the app gets laggier the more data the sensor measures. You're also only going to get a week of data for historical measurement.Other details are worth mentioning beyond the sensor accuracy and app integration, though. E-ink, as a display type, is just awesome. It looks very nice, aesthetically. Each refresh blanks the screen temporarily, though. Keep this in mind, if you decrease the measurement interval (you can measure as frequently as once per minute). Also, there's no backlight, which is why the battery life is good, but keep this in mind too, if you want to see it in the dark.I've taken this sensor on an airplane, and it works great there too. It's just an incredible sensor to have -- you can pocket it or bring it somewhere in a backpack and still have CO2 measurements, where most sensors can't go. For travel, or just in general, it's a great device to have. After calibration, it measures very accurately, and I'm happy with my purchase all around. However, I'd say calibration is mandatory.I've included a screenshot of a graph made from the CSV, as well as the CSV data from the unit itself.