Test of angles:
Measured with a 90 steel square with an internal angle perpendicularity tolerance of 0.13mm and an internal angle side length of 500mmx400mm. Place the short side of the square close to the short side of the plate? The long side of the square close to the long side of the plate? Use a feeler or vernier caliper to measure the maximum gap between the length of the plate and the long side of the square. When the length of the plate is less than or equal to 500mm? Any pair of opposite corners of the plate can be measured? When the long side of the plate is greater than 500mm? The four corners of the plate can be measured. The measured value of the maximum gap indicates the angle tolerance of the sheet? The measured value is accurate to 0.1mm.
Appearance quality inspection:
①Pattern color tone Put the plywood board and the inspection board flat on the ground? Stand at a distance of 1.5m from the board for visual inspection. ② Manual chisel mark Place the plate flat on the ground and visually inspect it at a distance of 1.5m from the plate. ③Number of color lines Visually measure the number of color lines. ④Missed corners and chipped corners Use a vernier caliper to measure the length, width, and height of the defect? Visually check the number of missing corners. ⑤Steps Use a vernier caliper to measure the height of the steps. The maximum value of the measurement is used as the height of the steps. ⑥Cracks Use visual inspection for visible cracks? Hammering for hidden cracks? That is, hitting the plate with a metal hammer? Identify whether there are cracks by sound? Generally mute? OK. ⑦Spots Use a vernier caliper to measure the size of the spots? Visually check the number of spots.
Marble is a relatively soft stone. In the Mohs hardness table, the grade of MOHS marble is about 3 degrees and the highest is 10 degrees. Marble is made of calcium like teeth. If you bite something that is too hard, your teeth will break? If you eat too much sugar, your teeth will perforate. The same is true for stone. If improper reagents are used on the surface of the stone, the stone will begin to rot, forming cavities. The following is the famous Mohs hardness table "MOHS". This standard was formulated in the early nineteenth century? It helps to identify the strength and hardness of the stone used? In order to take corresponding measures in application. For example, the lower hardness of the stone needs a softer reagent? The mopping frequency is more frequent.
Mohs Hardness Scale:
1. Talc 2. Gypsum 3. Calcite? Most marbles? 4. Fluorite 5. Apatite 6. Feldspar? Granite? 7. Quartz? Granite? 8. Topaz 9. Corundum 10. Diamond Mohs hardness scale It is used to measure the degree of wear resistance of the stone. When the sediment or gravel is harder than the stone surface? It will scratch the stone. For example, the hardness grade of hard plastic is about 2.0? It will not scratch the calcite (marble) of grade 3. Sand with a hardness of grade 6 will scratch grade 3 calcite but not grade 7 quartz or granite. The higher the hardness level? The more wear-resistant. The hardness of the foreign sediment in the building is 3.0 to 7.0