透明毛细管管壁折射率的无损测量

介绍了一种无损测量透明毛细管管壁折射率的方法。该方法利用平行光经过装有不同已知折射率标准液体的毛细管后会聚焦点位置不同的原理,通过CCD对会聚焦点位置成像后的图像进行判断,计算出毛细管外轮廓位置和焦距,进而计算出毛细管管壁的折射率,其测量精度可达0.005。分析了毛细管内外径对管壁折射率测量的影响,结果表明,管壁越厚,测量精度越高;同时对毛细管管壁折射率灵敏度和成像系统的景深值进行了计算和比较,结果显示,标准液体折射率越低,标定精度越高。该方法使用设备简单,操作方便,便于对图像观察和识别,实现了对毛细管管壁折射率的无损精确测量。

Nondestructive measurement of refractive index of transparency capillary

A novel nondestructive measuring method for the refractive index of a transparency capillary is introduced in this paper. When a collimated light passes through a capillary filled in a standard liquid with known refractive index, the focal position is dependent mainly on the wall-material of the capillary.On the basis of the above, the position and focal length of a capillary are imaged by a lens onto a CCD chip accurately, when the capillary is filled in two different liquids with known refractive indexes, respectively.Then, the refractive index of the wall- material is obtained by measuring and calculating two positions and focal lengths separately. The measurement accuracy of refractive index is better than 0.005. The effects of measuring parameters, including inner and outer diameters of the capillary, the refractive index of satandard liquid, as well as the image depth and sensitivity of refractive index on the measuring precision are analyzed. It is shown that the thicker capillary wall is,the higher the measuring precision is,and the lower the refractive index of standand liquid is,the higher the calibrating accuracy is. The introduced method is characterized by simple equipment, easy to operation, convenient to observe and its measurement precision of refractive index can meet the requirements of general scientific research and experiments.