一种精确测量微量液体折射率的新方法

摘 要：本文介绍了一种用玻璃毛细管精确测量微量液体折射率的新方法。这种方法基于共轴球面光学系统的成像原理，通过读数显微镜对吸入待测液体后毛细管的焦点位置进行单一参数的测量，进而计算出待测液体的折射率。用此方法测量了纯水、乙醇、乙二醇、丙三醇的折射率，各种待测样品的需要量小于0.002 ml；对纯水和乙醇样品，折射率测量精度优于0.0003；对乙二醇和丙三醇样品，折射率测量精度优于0.0007。选用适当的毛细管参数，可以进一步提高这种测量方法的测量精度，扩展折射率的测量范围。该方法具有待测液体用量极少、使用的设备简单、操作方便和折射率测量精度高的特点。论文对实验测量误差以及进一步提高测量精度作了详细的分析和讨论。

A new method for measuring the refractive index of micro-quantity liquid

On the basis of imaging principle of a coaxial spherical surface optical system,a new measuring method using glass capillary for the the refractive index of micro-quantity liquid was introduced.The refractive index was obtained through measuring the focal position of a capillary filled with the liquid by a reading microscope,and doing a calculation with an analytic formula.The refractive indexes of four liquid mediums,water,ethanol,ethylene glycol and glycerin were measured,the required sample was less than 0.002 ml,the precisions of obtained refractive indexes were better than 0.000 3 for water and ethanol,and 0.000 7 for ethylene glycol and glycerin.The results show that the new measuring method can be characterized by a micro-quantity sample,and has advantages in simple equipment,easy operation and high measurement accuracy.It is adapted to measure the refractive index of transparent or translucent micro-quantity liquid sample.