Aranet4 – CO2 COVID Ventilation

Monitors air quality at your home, in school, office or any other indoor private or public space.

Helps to reduce the risk of COVID-19 infection

Measures carbon dioxide (CO2) concentration, temperature, relative humidity and atmospheric pressure

Small, portable and easy to use




The Aranet4 sensor is a battery powered CO2 meter with additional measurements of temperature, relative humidity and atmospheric pressure.* The device is suitable for monitoring the CO2 level in indoor environments such as at home, in office or at school.

Measurement data are displayed on power-efficient e-ink screen allowing for long battery life. Additionally the device can provide a visual and sound notifications in case the CO2 level surpasses the high concentration level of 1400 ppm (parts per million) – level typically associated with complaints of drowsiness and poor air quality. 

Aranet4 uses the nondispersive infrared (NDIR) sensor to measure the concentration of CO2. The CO2 gas in the chamber absorbs infrared light and this absorption is measured by the sensor. The less light passes through – the higher the CO2 concentration. The CO2 gas absorbs only a specific wavelength of the light therefore an optical filter is used.

By using the Aranet4 app on your smart device it is possible to wirelessly access the real-time data and up to one week of historical measurement data. The app also allows to configure the Aranet4 device. The Aranet4 app supports connection of several Aranet4 sensors to monitor their parameters remotely from a single smart device. 

Additionally up to 100 Aranet4 PRO devices can be connected to the Aranet PRO base station. 

The Aranet4 sensor screen explained

  1. CO2 concentration level in ppm (parts per million).
  2. Temperature of the air in Celsius or Fahrenheit. Refer to the switch positions of the Aranet4 in chapter Switch positions explained.
  3. Relative humidity of the air (RH%).
  4. Battery level.
  5. Alarm status. The speaker symbol is visible when alarm function is activated. The alarm settings can be adjusted using the Aranet4 app. 
  6. Bluetooth status. If the Bluetooth symbol is visible the Bluetooth pairing function is enabled. Refer to switch positions of the Aranet4 in chapter Switch positions explained. Make sure Bluetooth connectivity is enabled on your smart device in order to connect to the Aranet4 device. 
  7. Radio status.** If the radio symbol is visible, the connectivity with Aranet PRO base station is enabled. Refer to switch positions of the Aranet4 in chapter Switch positions explained.
  8. CO2 indication mode. If the leaf symbol is visible the CO2 level indication is set to plant mode (plants require higher CO2 level than humans). If the leaf symbol is not visible, then CO2 level indication is set to human mode. You can select the mode using the Aranet4 app.
  9. CO2 threshold level indication.

When the human mode of the CO2 indication is selected:

Green represents normal level (below 1000 ppm)
Yellow represents average level (1000 to 1400 ppm)
Red represents high level (above 1400 ppm)


When the plant mode is selected:

Green represents normal level (above 500 ppm)
Yellow represents average level (500 to 300 ppm)
Red represents low level (below 300 ppm)


10. CO2 calibration mode indication. Symbol “A” is displayed when calibration is set to automatic. No letter is displayed when calibration is set to manual mode.

Technical Details

Sensor Performance

CO2 concentration


Relative Humidity

Atmospheric Pressure 1

Range 0 – 9999 ppm 0 – 50 °C 0 – 85 % 300 – 1100 hPa
Resolution 1 ppm 0.1 °C, (0.1 °F) 1 % 1 hPa
Accuracy 2 ± 50 ppm, ± 3 % of reading 3 ±0.3 °C, (±0.5 °F) ± 3 % ± 1 hPa
Long term drift N/A4 0.03 °C/year, (0.05 °F/year) 0.5 %/year 1 hPa/year
Time constant ? (63 %) 5 100 seconds 10 minutes TBD instantaneous

Radio parameters 6

Line of sight range 3 km (1.9 mi)
Supported ISM bands EU868, NA915
Transmitter power 14 dBm
Data transmission interval 7 1, 2, 5 or 10 minutes
Data protection XXTEA encryption
Compatible base stations Aranet PRO

Bluetooth Parameters

Line of sight range 10 m (33 ft)
Transmitter power 4 dBm or -12 dBm
Data transmission interval 1, 2, 5 or 10 minutes


TX interval Battery lifetime at 20 °C (68 °F) 9
1 minute 0.6 years
2 minutes 1.1 years
5 minutes 2.4 years
10 minutes 3.9 years


CE Conformité Européenne
IC Innovation, Science and Economic Development Canada
FCC Federal Communications Commission (USA)


Ingress Protection code IP20
Operating temperature range 0 °C to 50 °C, (32 °F to 122 °F)
Operating relative humidity range 0% to 85%
Dimensions 70 x 70 x 24mm, (2.76 x 2.76 x 0.94 in)
Weight 8 104 g (3.7 oz)
Enclosure material Polycarbonate
Included in the box 2 AA Alkaline batteries, configuration pin

Aranet4 is not impact resistant!

Do not leave the device in the direct sunlight!

1The device measures absolute pressure, i.e., the readings are not compensated for an elevation above the sea level.

295 % of the sensors measure within these typical limits in equilibrium state at the time of sale. For evaluation of the total measurement error long-term drift has to be taken into account.

3CO2 measurement accuracy is provided for a range 400 … 2000 ppm, temperature 15 … 35 °C (59 … 95 °F) and relative humidity 0 … 60 %. Accuracy above 2000 ppm is 10 % of reading, but not guaranteed since it is extrapolated form the calibrated range.

4If a drift of the CO2 measurements occurs, calibration option of the device should be used.

5Time constant is determined at 1 m/s airflow.

6Available only for the PRO version of the product.

7Due to regulatory requirements 1 minute data transmission interval is not available in Russia.

8Weight with alkaline AA Fujitsu LR6G07 Premium batteries.

9With the Bluetooth connection disabled. Battery lifetime data has been obtained by mathematical extrapolation and is provided for descriptive purposes only and is not intended to make or imply any guarantee or warranty. AA Fujitsu LR6G07 Premium batteries used for tests and calculations.

File Description File size Downloads
pdf Aranet 4 Sensor Manual 1 MB 67
pdf Aranet 4 Datasheet 232 KB 41
pdf How Aranet 4 helped to mitigate COVID-19 risks in Milan 1 MB 35