| Abstract Title: | How to measure accuralely coarse particles by using low-cost sensors |
| Presenter Name: | Dr Edurne Ibarrola-Ulzurrun |
| Co-authors/Co-presenters: | Mr Asier Galech Mr Javier Fernandez-Huerta |
| Company/Organisation: | Kunak Technologies |
| Country: | Spain |
Abstract Information :
Low-cost particle sensors have some limitations that must be solved in order to get the highest performance of the particle sensor.rn• Specific particle type in each location: Low-cost particle sensors measure the particle mass density with indirect means. They used an optical sensor that relies on light scattering to measure the number of particles and their size. rn• Accurate measurements of coarse particles: it exists several particle sensors that are not capable to measure accurate coarse particles (PM10) because they have few particle size channels (<5 channels). It is necessary more particle size channels (ca. >15 channels) to be able to measure coarse particles.rnOn the contrary to Equivalence Instruments, low-cost sensors are exposed to ambient conditions, meaning that the sample is not heated and dried before reaching the sensor (unless specified by the manufacturer). Thus, another issue to face up is the effect of the ambient conditions on the sensors:rn• Humidity Effect: Low-cost particle sensors are affected by hygroscopic effect in high humidity conditions.rn• Temperature Effect: Extreme temperatures can affect the sensor electronics, as well as the fan of the sensor, could stop. rnA new firmware with several improvements has been launched for the Kunak Air PRO particle measurements in 2022 to increase the accuracy under any environmental conditions compared to equivalence particle instruments. rnIn order to evaluate the new field performance achieved by the Kunak Air PRO, co-location field studies have been carried out in different countries under different particle types and environmental conditions. In Sundsvall (Sweden) from 1st to 25th of January 2022 and in Antwerp (Belgium) from 7th December 2021 to 7th March 2022.rnThe main objectives of the study were: (i) to evaluate the new improvements made on the PM sensor showing the field performance achieved by the Kunak Air PRO; (ii) to prove the performance of the sensor, is comparable to Equivalence Methods of laser scattering technology, for PM1, PM2.5, PM4, PM10, TSP and TPC, thanks to the particle sensor with 24 particle size channels, which can measure coarse particles accurately; and (iii) to show the performance of the humidity correction algorithm applied to the particle sensor and the low effect of extreme temperatures in the particle sensor.rnThe new particle sensor design has demonstrated excellent field performance, allowing accurate measurements in all the particle sizes (PM1, PM2.5, PM4, PM10, TSP and TPC) having an R2>0.85 for all the particle sizes and a MAE<5 µg/m3 for PM10 and <2 5µg/m3 for PM2.5. Besides, it is shown that the particle sensor accomplishes the requirements for indicative measurements according to the Directive 2008/50/EC, and even in some cases the requirements for equivalence instruments. Finally, thanks to the new design and algorithms implemented in the Kunak Air Pro, the effect of the humidity in the particle sensor is perfectly corrected and can be considered negligible, not requiring any kind of dryer or heater in the sensor-system. Besides, the assessment of the sensor in extreme cold temperatures shows no effect on the measurements, allowing an excellent performance of particle sensor.
