Kvalita vzhľadu bridlice Kvalita kontroly

1. With pattern and color tone, put the qualified board and the tested board flat on the ground, standing at a distance of 1.5m from the board for visual inspection.

2. Manually gouge the board flat on the ground, and visually inspect it at a distance of 1.5m from the board.

3. The number of color lines The number of color lines.

4. The length, width and height of the defect are measured with a vernier caliper; the number of missing corners is visually measured.