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1880年美国人贝尔发现“光声效应”,激光问世后,光声光谱技术进一步获得应用和迅速发展。光声光谱是以断续光周期性的照射置于密封池内的物质,物质吸收光能,其原子从低能态跃迁到高能态,若通过无辐射跃迁的形式将吸收的能量释放出来,则这部分能量使物质升温和膨胀,因而产生压力。该压力随断续光的照射频率周期性的变化,因而在光声池内形成压力波,即声波。实际检测中,常采用驻极体微音器作为声传感器来探测气体中的光声压力信号;用锁定
In 1880, the American Bell discovered the “photoacoustic effect”. After the laser came out, the photoacoustic spectroscopy technology was further applied and developed rapidly. Photoacoustic spectroscopy is based on the periodic exposure of intermittent light placed in the sealed pool of substances, substances absorb light energy, its atoms transition from a low energy state to a high energy state, if by radiation-free form of absorption of energy released, then Some energy causes the substance to warm and swell, creating stress. The pressure changes intermittently with the frequency of intermittent light irradiation, thus forming a pressure wave in the photoacoustic tank, that is, sound waves. In actual testing, often use electret microphones as acoustic sensors to detect the photoacoustic pressure signal in the gas; with locking