Development of ASTM International D8405—Standard Test Method for Evaluating PM_2.5 Sensors or Sensor Systems Used in Indoor Applications

Abstract

Sensors and sensor systems for monitoring fine particles with aerodynamic diameters smaller than 2.5 µm can provide real-time feedback on indoor air quality and thus can help guide actions to manage indoor air pollutant concentrations. Standardized verification of the performance and accuracy of sensors and sensor systems is crucial for predicting the efficacy of such monitoring. A new ASTM International standard test method (ASTM D8405) was created for this need and is the most exacting laboratory protocol published to date for evaluating indoor air quality sensors and sensor systems measuring particles smaller than 2.5 µm in diameter. ASTM D8405 subjects sensors and sensor systems to five test phases: (1) an initial particle concentration ramp; (2) exposure to various temperature and humidity conditions; (3) exposure to interfering particles; (4) temperature cycling; and (5) a final particle concentration ramp to assess drift. This paper discusses the development of the standard test method, key aspects of the testing process, example evaluation results, and a comparison of this standard test method against peer evaluation protocols.

Keywords:

• Air monitoring
• indoor air
• low-cost sensor
• particulate
• performance evaluation
• test standard

Acknowledgments

The authors would like to thank the many ASTM D22.05 subcommittee members and their colleagues for valuable comments during the balloting process that resulted in a refined and clear test method: Mike Brisson, Andrea Clements, Ian Cull, Rachelle Duvall, Richard Fox, Martin Harper, Geoff Henshaw, Al Hodgson, Sue Kimbrough, Paul Kremer, Hal Levin, Xiaoyu Liu, Stephany Mason, William Mills, Bud Offerman, Andy Persily, Dustin Poppendieck, John Saffell, Brett Singer, and Ashley Wiand. Additional appreciation is extended to South Coast AQMD Executive Management (Wayne Nastri and Jason Low) for the internal support to pursue this work. Joe Nebbia of Newport Partners, LLC and Mike Moore of Stator, LLC (formerly also at Newport Partners, LLC) are thanked for their significant contributions as test method reviewers and intermediaries between the ASTM D22.05 subcommittee and the laboratory activities. This work was conducted with Newport Partners, LLC through a collaborative agreement with the U.S. Department of Energy.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Additional information

Funding

This work was conducted using pass-through funding of a U.S. Department of Energy grant, in which the prime recipient was Newport Partners, LLC.