1800年,英国物理学家赫谢耳在用高灵敏温度计研究光谱里各种色光的热作用时发现,在光谱的红光区域外,温度也会升高。这就表明,在光谱的红光外侧,有一种不可见光的存在。后来,人们就把这种光线叫红外线或红外光。红外线也是一种电磁波。在太阳光谱中,从400μm——7600(?)波长的一段不可见光都称为红外 In 1800, when British physicist Hirshelm studied the thermal effects of the various colored lights in the spectrum with a highly sensitive thermometer, he found that the temperature outside the red region of the spectrum also increased. This shows that there is an invisible light outside the red light of the spectrum. Later, people put this kind of light called infrared or infrared light. Infrared is also an electromagnetic wave. In the solar spectrum, a section of invisible light from a wavelength of 400 μm to 7600 (Å) is called infrared