This standard specifies the scientific method for measuring the specular glossiness of various architectural surface materials (such as marble, ceramic tiles, plastic flooring, etc.). To accommodate materials with different gloss intensities, the standard defines three measurement angles: 20°, 60°, and 85°. The 60° angle is typically used for general measurements; the 20° angle is employed for high-gloss surfaces (with gloss units greater than 70) to enhance resolution; while the 85° angle is used for low-gloss surfaces (with gloss units less than 10). The core detection instrument is the gloss meter, which measures gloss by emitting a beam at a specific angle and precisely receiving the specularly reflected light from the sample surface. This method provides critical technical guidance for evaluating and standardizing the visual appearance of materials.