Long-Term Evaluation and Calibration of Low-Cost Particulate Matter (PM) Sensor
Long-Term Evaluation and Calibration of Low-Cost Particulate Matter (PM) Sensor
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DOI:
10.3390/s20133617
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发表时间:
2020-07-01
期刊:
影响因子:
3.9
通讯作者:
Lee, Dongjun
中科院分区:
文献类型:
--
作者:
Lee, Hoochang;Kang, Jiseock;Lee, Dongjun
Low-cost light scattering particulate matter (PM) sensors have been widely researched and deployed in order to overcome the limitations of low spatio-temporal resolution of government-operated beta attenuation monitor (BAM). However, the accuracy of low-cost sensors has been questioned, thus impeding their wide adoption in practice. To evaluate the accuracy of low-cost PM sensors in the field, a multi-sensor platform has been developed and co-located with BAM in Dongjak-gu, Seoul, Korea from 15 January 2019 to 4 September 2019. In this paper, a sample variation of low-cost sensors has been analyzed while using three commercial low-cost PM sensors. Influences on PM sensor by environmental conditions, such as humidity, temperature, and ambient light, have also been described. Based on this information, we developed a novel combined calibration algorithm, which selectively applies multiple calibration models and statistically reduces residuals, while using a prebuilt parameter lookup table where each cell records statistical parameters of each calibration model at current input parameters. As our proposed framework significantly improves the accuracy of the low-cost PM sensors (e.g., RMSE: 23.94 -> 4.70 mu g/m3) and increases the correlation (e.g., R2: 0.41 -> 0.89), this calibration model can be transferred to all sensor nodes through the sensor network.