gravimetric

Particulate matter with a diameter of ≤2.5µm (PM2.5) has been shown to be present in many buildings at concentrations that are harmful to human health. Accordingly, they should be used as metrics of indoor air quality (IAQ) and included in standards or norms. This paper uses measurements of PM2.5 concentrations made in three different environments using three different devices to show that there are barriers that must be before they can be considered viable diagnostics. Optical particle counters (OPCs) are a common device used to measure temporal changes in PM2.5 concentration.