取整卷宽度的样品一张，沿MD方向间隔一定距离裁取长不小于50mm，宽不

A sample of a full roll width, spaced a distance along the MD direction cutting-out length of not less than 50mm, 50mm wide sample is not less than 3 (holding the sample surface clean, smooth, non-contact measurement of the sample preparation area, not there are no visible scratches, contamination, foreign matter and abnormalities such as bending)

Take the width of the whole volume of a sample, along the MD direction interval of a certain distance cut length is not less than 50mm, width is not less than 50mm of the sample 3 pieces (the sample surface in the sample process to maintain clean, flat, non-contact area, can not have visible scratches, pollution, foreign objects and bending and other anomalies)

Take a sample of the whole roll width, and cut three samples with a length of not less than 50mm and a width of not less than 50mm along the MD direction at a certain distance (keep the sample surface clean and flat during the sample preparation process, do not contact the measuring area, and do not have visible scratches, pollution, foreign matters, bending and other abnormalities)