Response Characterization of an Inexpensive Aerosol Sensor

Area of Science:

• Environmental Science
• Atmospheric Science
• Sensor Technology

Background:

• Existing air quality monitoring networks suffer from low spatial coverage due to high costs.
• Inexpensive aerosol sensors offer a potential solution but lack documented accuracy and response characteristics.
• Evaluating low-cost sensors is crucial for expanding air quality monitoring capabilities.

Purpose of the Study:

• To evaluate the accuracy and response characteristics of inexpensive Shinyei PPD42NS and PPD60PV aerosol sensors.
• To compare laboratory findings with field experiment validation.
• To determine the suitability of these sensors for specific particulate matter (PM) size fractions.

Main Methods:

• A novel laboratory evaluation method using a Vibrating Orifice Aerosol Generator to create a continuously changing, monodisperse particle size distribution.
• Generation of particulate mass (PM) concentration stimulus.
• Field experiment validation against a medium-cost optical dust monitor.

Main Results:

• Both sensors responded to particulate mass concentration, not number concentration.
• PPD42NS sensor showed highest detection efficiency for particle sizes 2.5-4 µm; PPD60PV for 0.7-1 µm.
• Field tests showed high PM correlations (R² = 0.962 for PPD42NS, R² = 0.986 for PPD60PV) within viable detection ranges.

Conclusions:

• The PPD42NS sensor is suitable for indicative measurement of PM_10-2.5 (2.5-10 µm).
• The PPD60PV sensor is potentially useful for measuring PM_2.5 (< 2.5 µm).
• These inexpensive sensors can complement existing air quality networks, providing valuable data for specific particulate matter fractions.