【摘要】 以波长为266nm的激光为激发光源,采用脉冲光声光谱技术,用自制的光声探测装置对SO2分子的光声吸收特性进行了实验研究,获得了室温、665Pa气压的实验条件下声音在SO2气体中的传播速度。通过测量光声信号随实验条件的变化发现,光声信号强度随激光能量的增加而增大,随缓冲气体压强升高而增大,缓冲气压增加到约2.66×104Pa时出现饱和现象。在标准大气压情况下,测量了痕量SO2气体的浓度,采用这套光声探测装置,SO2气体探测灵敏度可以达到9.1×10-6。更多还原

【Abstract】 SO₂ is one of the major air pollutants.The absorption property of this molecule was tentatively surveyed with the technique of photoacoustic（PA） and with laser radiation of 266 nm as excitation source.The velocity of the sound in SO₂ gas was measured under the conditions of room temperature and 665 Pa gas pressure.The intensity of PA signal is correlated with the experimental conditions.It shows that the PA signal is enhanced with both of the laser energy and buffer gas pressure.Optical-acoustic signals appear saturation when the buffer gas pressure is increased to about 2.66×104 Pa.Trace concentrations of SO₂ are detected under ambient conditions with this technique.The limit of detection of 9.1 ppm is obtained for SO₂ in air.更多还原