Aerosol Measurement Degradation in Low-Cost Particle Sensors Using Laboratory Calibration and Field Validation

Area of Science:

• Environmental Science
• Sensor Technology
• Public Health

Background:

• Growing concerns about air pollution necessitate accessible monitoring tools.
• Low-cost sensors enable widespread deployment and citizen science participation.
• The AirU sensor is a candidate for such applications.

Purpose of the Study:

• To evaluate the performance and reliability of the AirU low-cost particle sensor.
• To assess sensor degradation after field use through calibration comparisons.
• To validate AirU readings against a reference instrument in an indoor setting.

Main Methods:

• Comparing pre- and post-deployment calibration equations for 24 AirU sensors.
• Conducting an in-home comparative study of 3 AirU sensors against a GRIMM 1.109 reference instrument.
• Analyzing data for sensor drift and accuracy within defined tolerances.

Main Results:

• Pre- and post-deployment calibration showed minor changes, indicating limited sensor degradation.
• AirU sensors generally underestimated minimum and overestimated maximum particulate matter concentrations.
• ~88% of AirU sensor results were within ±1 μg/m³ of the GRIMM reference instrument.
• The AirU sensor demonstrates good performance for exposure assessment.

Conclusions:

• Low-cost AirU particle sensors are valuable tools for air pollution exposure assessment, particularly for citizen science initiatives.
• While some sensor degradation occurs over time, it is unlikely to significantly impact overall data quality for many applications.
• Further research is recommended to explore AirU performance in diverse environments and identify degradation sources.