Relationship between the concentrations of PM2.5 indoors obtained by using the optical and gravimetric methods: preliminary analysis

The paper presents preliminary analysis of measurements of the mass concentrations of PM2.5 in the indoor environment, obtained with the use of two optical instruments: (Grimm device and low-cost sensor) and a sampler based on the gravimetric method (SKC). It was found that the measurement of PM2.5 using an optical device with active sampling underestimates the actual mass concentration of this mode (PM2.5), while measurement using an optical device with passive sampling of air overestimates the concentration of PM2.5. It has been shown that the physical relationship between the mass concentrations of airborne particles obtained with an optical sensor (Csensor) and concentrations obtained with the gravimetric method (Cgrav) is not linear. However, for practical reasons, the correct (“true”) concentration levels of PM2.5 in an indoor environment can be estimated by converting sensor data according to a simple linear equation, i.e., Cgrav = a Csensor. The coefficient a for the sensor used was estimated at 0.45.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).