product grade

• 产品档次

product grade的用法和样例：

例句

1. With improvement unrefined potassium chloride is directly subjected to carbonization and therefore raises the product quality with similar cost.
   新工艺的主要改进为氯化钾原料不经精制而直接碳化，从而在成本相仿的情况下提高了产品档次。