Influence of environmental conditions, operational procedures, and filter material on robotic gravimetric weighing of particulate matter filters

Accurate measurement of particulate matter (PM) filter mass is crucial for reliable air quality monitoring and effective environmental management. This study investigates the influence of operational procedures, environmental conditions, and filter material on the performance of a Robotic Weighing System (RWS), with implications for improving gravimetric methods used in environmental assessment. Under stable environmental conditions (21 °C and 45% relative humidity), pre-conditioning filters inside the RWS did not significantly affect filter mass, as confirmed by factorial ANOVA. However, minor but statistically significant variations were observed during extended weighing sequences, suggesting subtle operational drift over time. Comparative analyses of PTFE, quartz, and glass fiber filters revealed that material properties influence mass stability, with glass filters exhibiting the lowest variability. Importantly, RWS measurements were consistent with manual scale results, supporting the reliability of automated weighing systems under controlled conditions. These findings support the use of robotic systems as a standardized, high-precision alternative to manual weighing, enhancing the quality and efficiency of PM monitoring networks. Given the large number of filters processed in national air monitoring programs, automation offers a high-precision, efficient alternative, supporting robust long-term PM monitoring. These findings are particularly relevant in the context of the new air quality directive, emphasizing the need for standardized, accurate measurements in regulatory compliance and environmental assessment.