Preliminary research for low-cost particulate matter sensor network

Low-cost particulate matter (PM) sensors may be suitable for indicative air quality measurements thanks to their small dimensions and high spatial resolution. Three different sensor types were selected for investigation in this study with specific focus on a Honeywell HPMA115S0 sensor to find out its usability at outdoors, perform load and long-term tests. The load test showed that the sensor calculates PM10 based on measured PM2.5 values. The analysis shows a break in calculation method at 25 μg/m3 PM2.5, and the calculation method for PM10 varies from 25 μg/m3 by around 81 μg/m3. Parallel test performed with different sensor types has shown that the protective cover formed by lamellar exterior does not affect the accuracy of the sensors, no accumulation or loss of sensitivity occurs. Long-term measurements have shown that the concentration values measured by the Honeywell sensor during outdoor measurements require humidity compensation, over 90% relative humidity (RH) the Pearson correlation coefficient (R) between the reference and sensor PM2.5 concentrations decreased by 0.3.