Air agencies and non-governmental organizations need to know the performance capabilities of low-cost sensors. In response, STI evaluated the performance of low-cost NO2 sensors and assessed their potential usefulness for gradient studies of near-roadway NO2 concentrations and citizen monitoring of air pollution.
For this evaluation, we developed
  1. Protocols involving the design of environmental testing chambers to hold the experimental sensors (instruments).
  2. Experimental designs for simultaneous measurement of target gases and interference with both reference analyzers and the low-cost instruments.
  3. Unique data acquisition, processing, and analytical protocols.
As part of this study, we explored
  • Sensor response to NO2 and ozone.
  • Cross-sensitivity and relative humidity effects.
  • Response (such as time lag) to changes in concentration.