qualitative index的用法和樣例：
例句
- The diameter control is one of the important quality index for spiral welded steel pipes.
螺旋焊接鋼管的直徑控制是螺旋焊管生產的重要質量指標之一。 - Based on the traditional production techniques, the article introduces improved production techniques and production quality index of Zizhong Mustard Tine.
本文介紹了在傳統生產工藝基礎之上進行改進了的資中冬尖生產工藝及產品質量指標。
