System Overview: This system is designed to address the challenges of sampling from open sources. It features stability, reliability, efficient collection, and ease of operation, making it suitable for indoor studies on non-online classification of particulates. The system employs a conventional filtration method for sampling, using a sample delivery system to transport dried and sieved powder samples to a resuspension chamber, where the particles are re-suspended. The sample is then collected onto a filter membrane using an impact sampler. Performance Features: Stable and Reliable Resuspension Chamber: Ensures uniform distribution of particulates and provides a longer residence time within the chamber. It is equipped with a pressure balance port to maintain pressure equilibrium inside the chamber. Efficient Airflow Design: The sample delivery pathway facilitates particle suspension, while the sampling pathway provides stable, pulsation-free constant flow. The recirculation of airflow significantly reduces system complexity. Particle Size Fractionation: The system features two independent sampling channels, allowing simultaneous collection of PM₁₀, PM₂.₅, and PM₁ across different particle size distributions.