Slate Size test methods

Stone divided into two, one for one side polished stone, and the other two panel without grinding stone plane.

    (1) The flat side of the grinding stone thickness limit tolerance measurement method

     Vernier caliper with readings 0.1MM measured midpoint four sides. With the difference between the maximum thickness of the same block board and minimum thickness represents the thickness between the very poor. Contract floor thickness of 10MM, allow poor of plus or minus 1.00MM
   
    (2) the length and width measurements

     Steel ruler with a reading of measuring 1MM. Length, width were measured three straight, with the average value