whiteness meter

例句：

1. 1. The whiteness meter on the wall is very accurate.
   墙上的白度计非常准确。
2. 2.The whiteness meter was used to measure the color of the paint.
   白度计被用来测量油漆的颜色。
3. 3. The whiteness meter showed that the fabric was not as white as it should be.
   白度计显示，这种布料的白色不如它应该的那样白。