spectral density meter

例句：

1. 1.The spectral density meter was used to measure the intensity of light.
   光谱密度计被用来测量光的强度。
2. 2. The spectral density meter was used to analyze the chemical composition of the sample.
   光谱密度计被用来分析样品的化学成分。
3. 3. The spectral density meter was used to detect the presence of certain chemicals in the air.
   光谱密度计被用来检测空气中某些化学物质的存在。