先后采用平行光法和透镜成像法获得光斑, 比较这两种光斑对线阵CCD数据采集稳定性的影响。结果显示采用透镜成像法获得的光斑更窄、亮度更均匀、边界更清晰锐利, 线阵CCD数据采集的稳定性更高。提出了普通透光玻璃的拉丝形成抛物柱面透射光栅的模型, 解释了光斑出现明暗相间条纹和光斑波形上出现小峰的原因。小峰造成线阵CCD采集数据出现错误, 光斑像元值不稳定。采用光学玻璃作为透光玻璃, 消除了光斑波形上的衍射小峰, 有效地控制了光斑像元值的采集误差, 提高了测氧仪的稳定性和测量精度。

The parallel light method and lens imaging method are used to generate light spots, and the influence of the light generating method on the stability of linear CCD is investigated. The lens imaging method generates a narrower and more homogeneous light spot with sharper border, resulting in a higher stability of the CCD data. In order to explain the fringe pattern and small peak on the light spot, a wire drawing induced parabolic cylinder transmission grating model of the normal glass is proposed. The results show that the CCD data error and the instability of the pixel of the light spot are resulted from the small peaks. As an improved method, the optical glass instead of normal glass is used as the transmission glass. The method can reduce the diffraction peak of the light spot and the error of the pixel, and enhance the stability and accuracy of the magnetomotive oxygen detector.