Accuracy of test plate: according to the national standard metrological verification regulations, it is divided into five grades: 00, 0, 1, 2 and 3 respectively.

The inspection plate shall be made of high-quality fine gray cast iron or alloy cast iron, and its working surface hardness shall be 170~220HB.

Inspection of surface quality of flat plate: inspection by painting. Level 0, 1 flat plate shall have at least 25 points, and level 2, 20 points and level 3, 12 points shall be within 25mm square on each side.

Scraping technology should usually be used to check the flat working surface. The maximum allowable value of surface roughness Ra is 5μm for the three-level plane working face with scraping processing.

Specification of inspection plate (length× width) 200mm×200mm-3000mm×6000mm Detailed technical parameters of inspection plate: specification (length× width) mm Accuracy class 0 1 2 3 Flatness tolerance (micron) 200× 200 510 20.5 200× 300 5. 22 300×300 5.5 1 1 22 300×400 6 12 24 400×400 6.5 12.5 25 400× 500 6.5 13 26 66 500×500 6.8 1 4 28 68 400×600 7 14 27.5 70 500×600 7 14.2 28.5 7 1 500×800 8 1 5.5 3 1 78 600×800 8 16 32 80 1 000×750 9 18 36 90 1000× 1000 10 20 40 97 1000× 120 0 10 20.5 4 1 103 1 000× 1500 1 1 22 45 1 12 1000×2000 26 52 130 1500×2 000 28 56 140 2000×2000 3 / kloc-0/ 6 1 153 2000×2500 34 67 168 1500×3000 35 70 174 2000×3000 37 74 184 2000×4000 44 88 2 19