Yes, there is a practical reason for choosing 10 microns as the standard filtration level. In an online system like TOR-5, the main objective is to remove circulating mechanical contaminants that can damage pumps, valves, and sensors, while keeping hydraulic resistance low for continuous operation. Finer filters (1-3 µm) would increase pressure drop, clog much faster, and require frequent replacement, reducing reliability. Since critical insulation particles are mostly managed by oil processing and not by online monitoring, 10 µm is a good compromise between protection, stability, and maintenance intervals.