* Download datasheet *
Where is it found?
CO2 is a result of normal cell function and is breathed out of the body. Besides, it is an essential element in photosynthesis, the process by which plants make food and energy. Levels of atmospheric CO2 have increased since the Industrial Revolution.
The primary causes are deforestation and the burning of fossil fuels such as coal, for electricity, heat production and transportation (cars, ships, planes, etc.). It could also be formed as a secondary pollutant by CO oxidation.
Why is it harmful?
Carbon dioxide (CO2) is the fourth most abundant gas in the Earth's atmosphere and a major greenhouse gas. It is an odourless, colourless gas whose emissions contribute to the global environmental problem of climate change.
CO2 contributes to ocean acidification and, at high concentrations, can displace oxygen (O2) and nitrogen (N2). CO2 is removed from the atmosphere when it is absorbed by plants and algae as part of the biological carbon cycle.
CO2 cartridge
The CO2 cartridge has a built-in non-dispersive infrared sensor (NDIR), ideal for measuring typical atmospheric concentrations for climate change applications (300–400 ppm), as well as high concentrations from industrial processes (up to 5,000 ppm). The cartridge includes an automatic baseline correction (ABC) algorithm to background levels to maintain long-term stability.
Technical specifications
| Type | NDIR (Non-Dispersive Infrared Sensor) |
| Unit of measurement | mg/m3, ppm |
| Measurement range (1) | 0–5,000 ppm |
| Resolution (2) | 0.01 ppm |
| Operating temperature range (3) | -20 to 50 °C |
| Operating RH range (4) | 0 to 99 %RH |
| Recommended temp. & RH range (5) |
-20 to 50 °C 15 to 95 %RH |
| Operating life (6) | > 4 years |
| Guarantee range (7) | — |
| Limit of Detection (LOD) (8) | — |
| Repeatability (9) | — |
| Response time (10) | < 30 sec |
| Typical accuracy (12) | ± 20 ppm |
| Typical precision R2 (11) | > 0.8 |
| Typical slope (11) | 0.6–1.66 |
| Typical intercept (a) (11) | -170 ppm ≤ a ≤ 170 ppm |
| DQO - Typical U(exp) (13) | — |
| Typical intra-model variability (14) | < 0.5 ppm |
- Measurement range: Concentration range measured by the sensor.
- Resolution: Smallest unit of measurement that can be indicated by the sensor.
- Operating temperature range: Temperature interval at which the sensor is rated to operate safely and provide measurements. In the PM sensor Type A: -40 to 50 °C with heater (more information on this version on request).
- Operating RH range: Humidity interval at which the sensor is rated to operate safely and provide measurements.
- Recommended RH range: Recommended relative humidity range for optimal sensor performance. Continuous exposure outside the recommended range may damage the cartridge.
- Operating life: Time period during which the sensor can operate effectively and accurately under normal conditions.
- Guarantee range: Concentration range covered by Kunak's guarantee.
- LOD (Limit of Detection): Measured at laboratory conditions at 20 °C and 50% RH. The limit of detection is the minimum concentration that can be detected as significantly different to zero gas concentration, calculated according to the Technical Specification CEN/TS 17660.
- Repeatability: Measured at laboratory conditions at 20 °C and 50% RH. Closeness of the agreement between the results of successive measurements of the same measurand carried out under the same conditions of measurement, calculated according to the Technical Specification CEN/TS 17660.
- Response time: Time needed by the sensor to reach 90% of the final stable value.
- Typical precision – R2, slope and intercept: Statistics obtained between the device hourly measurements and reference instruments in field tests between -10 to +30 °C at different locations. For the type B PM sensor, the expected error for PM10 is higher in the presence of coarse particles.
- Typical accuracy: For criteria pollutants, this is the average Mean Absolute Error (MAE) obtained between the device hourly measurements and reference instruments for 1 to 8 months of field tests between -10 to +30 °C in different countries. For other pollutants, it is the expected error of the measurement at the reading.
- DQO - Typical U(exp): Data Quality Objective expressed as the Expanded Uncertainty in the Limit Value obtained between the device hourly measurements and reference instruments for 1 to 8 months of field tests between -10 to +30 °C in different countries, calculated according to the European Air Quality Directive 2024/2881 and the Technical Specification CEN/TS 17660. For the type B PM sensor, the expected error for PM10 is higher in the presence of coarse particles.
- Typical intra-model variability: Calculated as the standard deviation of the three sensor means in 1 to 8 months of field tests between -10 to +30 °C in different countries.
A, B, C, D superindex: The super indexes refer to different types of cartridges related to the same target pollutant but with different technical specifications.
