data on SO2
SENSOR-BASED | BEST AVAILABLE ACCURACY
Where is it found?
Sulfur Dioxide (SO2) is invisible and has a nasty smell. It is produced by the combustion of any substance that contains sulfur. The main source of SO2 in the atmosphere comes from the combustion of coal or fossil fuels while small sources are in metallurgy and naturally by volcanic eruptions.
Locomotives, ships and other vehicles that burn fuel with a high sulfur content are other emission sources. Besides, it can react with other compounds in the atmosphere contributing to particulate matter pollution.
Why is it harmful?
SO2 gas is a respiratory tract and eye irritant that affects very fast to humans (10-15 minutes). Long exposures affect lung defences and aggravate the existing cardio vascular disease.
It also causes damage to ecosystems and it contributes to acid rain when oxidized to sulfuric acid. This provokes acidification of ecosystems, injuries and necrosis in vegetation and deterioration of materials.
The Sulfur Dioxide cartridge has a built-in electrochemical sensor which presents high cross-sensitivities with O3 and NO2. When used together with the NO2 and O3 cartridges, the Kunak algorithm is capable of correcting these cross-sensitivities improving the accuracy of the measurements.
However, it is not recommended for outdoor applications requiring accurate SO2 measurements at very low concentrations (<20 ppb).
- 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.
- Operating RH range (Recommended RH range): humidity interval at which the sensor is rated to operate safely and provide measurements.
- Operating life: lifetime of the sensor at normal conditions.
- Guarantee range: limit covered by the guarantee.
- LOD (Limit Of Detection): measured at laboratory conditions at 20ºC and 50% RH. The limit of detection is the minimum concentration that can be detected as significantly different at zero gas concentration, based on the metric from the Technical Specification CEN/TS 17660-1:2022.
- Repeatability (measured at laboratory conditions at 20ºC and 50% RH): closeness of the agreement between the results of successive measurements of the same measure carried out under the same conditions of measurement, based on the metric from the Technical Specification CEN/TS 17660-1:2022.
- Response time: time needed by the sensor to reach 90% of the final stable value.
- Statistical metric: statistics obtained between hourly measurements of the device and the reference instruments for 1 to 8 months field test between -10 to +30 ºC in different countries. (*) The expected error for PM10 is higher in presence of coarse particles.
- DQO-Typical U(exp): Data Quality Objetive expressed as the Expanded Uncertainity in the Limit Value obtained between hourly measurements of the device and the reference instruments for 1 to 8 months field test between -10 to +30ºC in different countries, based on the metric from the European Air Quality Directive 2008/50/EC and from the Technical Specification CEN/TS 17660-1:2022. (*) The expected error for PM10 is higher in presence of coarse particles.
- Typical intra-model variability: calculated as the standard deviation of the three sensor means in 1 to 8 months field test between -10 to +30ºC in different countries.