"GB/T 7702.20-2025" is the latest part of the series of standards "Test Methods for Coal Particles Activated Carbon", which specifies how to determine the total pore volume and specific surface area of coal particles activated carbon by gas adsorption method (usually using BET method). The standard describes in detail the determination principle, sample pretreatment, test steps and result reports, aiming to provide a unified and reliable methodological basis for quality control, performance evaluation and trade of activated carbon products. The new standard was implemented on November 1, 2025, replacing the old version of 2008.