The method is simple : put 8 12 pieces of floorboards together on flat ground . check combination for flatness and smoothness as well as the right tongue - groove osculation that should be neither too loose nor too tight by way of hand feeling and visual observation to judge the processing precision 举例而言,广州的年平衡含水率为17 . 3 ,那么在广州市场销售的木地板的含水率就应该在717 . 3之间,含水率高于17 . 3或低于7的木地板都是不合格产品。