* Download datasheet *
Where is it found?
Volatile Organic Compounds (VOCs) can be produced by fuel combustion (wood, coal, gasoline, etc.) from sources such as vehicles and industries. They can be released into the atmosphere through the evaporation of gasoline, paint and solvents from above-ground storage tanks. Another important emission source is biogenic: natural release by vegetation.
Why is it harmful?
Many VOCs are toxic and can cause cancer, mutations and/or other serious health problems. One of the most harmful compounds is benzene, which can cause leukaemia. Some of them contribute to ozone formation, with associated health, environmental and climate effects.
They also contribute to the formation of CO2 and secondary organic aerosols that can warm and cool the atmosphere, respectively.
VOCs cartridge
The Volatile Organic Compounds cartridge has a built-in photoionization detector (PID) sensor equipped with a 10.6 eV light energy source to accurately measure hundreds of VOCs commonly found in indoor and outdoor environments. Its cutting-edge design avoids any undesirable humidity effect, giving 10,000 hours of continuous operation.
To cover different applications, there are two measurement ranges:
- Type A: Detects low ppb concentrations in outdoor ambient environments. The Kunak algorithm corrects temperature, humidity and pressure variations, allowing accurate measurements from very low concentrations (< 5 ppb) up to 3,000 ppb, with very low variability between sensors.
- Type B: A higher range version that can measure up to 40 ppm. It is not recommended to use this cartridge to detect levels below 1 ppm, since the accuracy of the sensor at low concentrations decreases.
Technical specifications
| Type | Photoionization detector |
| Unit of measurement |
µg/m3, ppb (A) mg/m3, ppm (B) |
| Measurement range (1) |
0–3,000 ppb (A) 0–40 ppm (B) |
| Resolution (2) |
1 ppb (A) 0.01 ppm (B) |
| Operating temperature range (3) | -40 to 60 °C |
| Operating RH range (4) | 0 to 99 %RH |
| Recommended RH range (5) | 0 to 99 %RH |
| Operating life (6) | 10,000 hours |
| Guarantee range (7) |
50 ppm (A) 60 ppm (B) |
| Limit of Detection (LOD) (8) |
1 ppb (A) 0.01 ppm (B) |
| Repeatability (9) |
5 ppb (A) < 0.02 ppm (B) |
| Response time (10) |
< 12 sec (A) < 10 sec (B) |
| Typical accuracy (12) | — |
| Typical precision R2 (11) | — |
| Typical slope (11) | — |
| Typical intercept (a) (11) | — |
| DQO - Typical U(exp) (13) | — |
| Typical intra-model variability (14) |
< 3 ppb (A) < 0.1 ppm (B) |
- 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.
