掠射法测液体折射率实验中的几个问题

SEVERAL PROBLEMS OF MEASURING LIQUID REFRACTIVITY BY GRAZING METHOD

The measurement of liquid refractive index by grazing met- hod is based upon the principle of total reflection.In the past the deduced formula was mostly derived from critical rays.To process in this way,the essence of energy propagation of critic- al rays was not revealed.The author offers an alterative deduc- tion method by taking limit to get the formula so as to meet the physical process of occurring half shade.This eases to fully understand the knowledge concerning optics,especially the inte- rference fringes that occur in experiment & is helpful to deter- mine the half shade orientation rapidly & accurately.It also su- ggests a simple method to observe the interference of light when penetrating through film.