lumen meter

例句：

1. 1. The lumen meter was used to measure the brightness of the light source.
   使用光度计来测量光源的亮度。
2. 2. The lumen meter was used to measure the brightness of the light source.
   使用光度计来测量光源的亮度。
3. 3. The lumen meter was used to measure the brightness of the light source.
   使用光度计来测量光源的亮度。