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Oregon DEQ’s Prototype PM 2.5 Monitor


The Oregon Department of Environmental Quality (Oregon DEQ) has developed the SensOR™ – a less expensive, flexible continuous air quality monitoring solution that is enhancing its particulate matter 2.5 monitoring network throughout the state. With a price averaging much less than previous technology, these modules are enabling the agency to significantly expand its network.

In 2017, the Oregon Legislature approved funding for Oregon DEQ to install and operate 30 new particulate monitoring sites. To stay within funding constraints, Oregon DEQ built and programmed its own low-cost sensor platform – SensOR™. The modules run on low amp 120V A/C power (or in the future, solar panels) and use off-the-shelf sensors and parts from various manufacturers and code developed in-house based on open-source libraries. Unlike most commercial low-cost offerings, the modules’ data output easily integrates with existing data acquisition software. A module costs approximately $2,000, including an auto-zero solution and robust cellular modem. In contrast, each Federal Equivalence Method monitor costs the state $5,000 to $30,000, and they are more expensive to operate and maintain.

Oregon DEQ’s Air Quality Monitoring group is also developing metrological procedures and quality control checks to improve the modules’ data quality for informational purposes. The modules are being tested against known standards to ensure data generated are usable and of known quality. This enables Oregon DEQ to use the SensOR™ to provide near real-time data to Oregonians through the Air Quality Index (AQI) and AirNow. Additional uses include research, local exposure monitoring, increased coverage, improved spatial and temporal resolution, source identification, emergency monitoring, education, and community engagement.

As agencies seek to augment their ambient air quality monitoring data to improve decision-making and provide more information to the public, low-cost sensors will be an essential tool allowing agencies to conserve resources and address air quality issues.

For more information, view this video on the project or contact Matthew Shrensel of Oregon DEQ.