Leveraging Low- and Mid-Cost Sensors to Measure Ambient Greenhouse Gas Concentrations

Low and mid-cost indoor air quality sensors offer a versatile platform for quantifying greenhouse gas (GHG) emissions in cities and other urban regions. Their compact size enables their deployment in diverse locations where higher-cost traditional instrumentation installations are not feasible, and their lower-cost allows a substantially larger number of them to be deployed in a measurement network. Though these are beneficial characteristics, their reduced accuracy impacts the value their data brings to GHG network analyses aimed at transforming concentration data to emission estimates.

The National Institute of Standards and Technology (NIST) Greenhouse Gas Measurements Program has been exploring low- and mid-cost sensor performance metrics as part of the deployment of approximately 50 mid-cost GHG sensor packages within the larger US Northeast Corridor tower based GHG observing network. We aim to share our lessons learned to benefit others looking to deploy and scale GHG and AQ measurement networks comprised of low- and mid-cost sensors.

In this talk, we will discuss sensor performance assessment methods employed at NIST to evaluate low- and mid-cost carbon dioxide (CO₂) sensors, and how we characterize these sensors prior to deployment in the field. We will also highlight the design of our custom, modular sensor package, emphasizing the importance of a flexible and scalable design. Additionally, we will showcase how a microservices-based system software architecture can allow for seamless sensor changes in the field without disrupting existing data collection procedures, guaranteeing a high quality of data from deployed packages.