原子吸收法的原理在于测定样品中被测元素对空心阴极灯发射的该元素特征谱线的吸收。一般,灯发射线的半宽度约为0.002纳米,吸收线的半宽度稍宽,约为0.004纳米。测定时,仪器的单色器调到待测元素的特征波长,光谱通带为0.2～0.5纳米左右,比空心阴极灯发射线宽度大两个数量级。 The principle of the atomic absorption method is to determine the absorption of the elemental characteristic line emitted by the element under test in the sample to the hollow cathode lamp. In general, the half-width of the light emission line is about 0.002 nm, and the half-width of the absorption line is slightly wider, about 0.004 nm. Measurement, the instrument monochromator tune to the characteristic wavelength of the element under test, the spectral passband of about 0.2 to 0.5 nm, hollow cathode lamp emission line width two orders of magnitude larger.