基于直角棱镜的气体传感器在能见度测量中的应用

用基于两个相同直角棱镜构成的气室,以不同的灵敏度分时测量气室的输出光强度,来测定大气消光系数,再根据科施米德(Koschmieder)定律计算大气能见度。测试结果表明,用基于直角棱镜的气室测量的数值与直接透射法所测的数值具有很好的相关性,相关系数为0.98;直角棱镜底面的轻度污脏对测量的影响可不考虑,该方法抵抗环境污染影响的能力较强,提高了长期可靠性。气室输出光束被聚焦后,用光纤束接收并传输到光电探测器,有效抑制了旁轴光束的干扰,光纤分布的不均匀性产生的附加误差小于2.0%。将暴露大气中的光学元件加热,控制了结露现象产生的影响。

Application of Gas Sensor Based on Rectangular Prism in the Monitoring of Atmospheric Visibility

A new method of measuring the atmospheric visibility is introduced. Atmospheric extinction coefficient is measured with the cell, which is constructed with two same rectangular prisms, and then the visibility is decided by Koschmieder′s law. The measurement is carried out at different sensitivity time-sharing. As a result, there is a correlation between the visibility data measured with the cell and with direct transmission. The relative coefficient is about 0.98. The influence of light dirty on the surfaces of the prisms is ignored. The method can restrain the influence from surroundings, and the long reliability of the set is improved. After the beam of light from gas cell is focused, it is incepted by the fiber bundle and transmitted into detector. The beam of light off-axes is kept from the bundle. Add-error from asymmetry of fiber distribution is less 2.0%. Influence from moisture on the surfaces of optical components uncovered in air is removed with heating the components.