What kind of marble and granite blocks? Marble and granite in several grades? How to divide
National environmental certification can be used for indoor, that is, Class A stone, radon concentration of less than 70 Bb / cubic meter, and the purchase, we must choose the regular manufacturers of products. Class A stone (within the scope of use is not limited) Radiation concentration in the range of radiation is less than 70 Bb / m3, Class B stone (not used in the interior of the room, can be used for all other buildings inside and outside) 90 Baker / cubic meter, C class stone (can be used for all building exterior) less than 100 Bb / m3. Marble is radiant, and some marble is also very high radiation, but the current decoration with the marble radiation is within the scope of the provisions of the national security, the body has no effect, very slight, some of the higher radiation marble, the country Only allowed for outdoor decoration, for the interior decoration of the marble are detected by the security sector, so you can rest assured that the use of marble in general is the darker the greater the color radiation, but not because he said he was sure There is a lot of radioactive pollution, marble is divided into artificial marble and natural marble, artificial marble does not exist radiation problems, natural marble radiation. In general, the radioactivity of marble than the low activity, not enough to worry about. Granite radioactive specific activity, red> light red> gray> white, black. While the radioactive than the activity of imported stone, the relative domestic stone to be high.
If there is no special words are generally used to eat a lot of material
Also stone cleanliness
Grade are divided into three, A, B, C, etc., A and so the highest, C and so the lowest.
The size of the length of the shortest height and height of the shortest position, size and then deduct 10cm, 5cm, 5cm, which is the standard method. There is a large angle, should be deducted the actual size of the missing angle occupied volume
