Measurement Of Solution Properties By Using Grating Diffraction

Since1972, that T.R. Pryer, who came from Canadian National Institute, had put forward a method to make a measurement using diffraction with the light of laser. It began to form a method that could make a precision measurement for different physical property by finding the changes of diffraction fringes obtained by using laser to irradiate the object to be measured. This optical method has advantages of easy to use, fast to response, precious to measure and cheap to buy.Therefore, the diffraction measurements had always been a matter of great importance, which gradually developed into an optical measurement technology disciplines.This article precisely makes the use of the diffraction of grating, which can get the measurement-related nature of the solution.For the theoretical side, we start from the Maxwell equations, make use of electromagnetic nature of the light, and analyze this particular solution to the mediums, got a light variation of the refractive index of the solution, and to define the refractive index varies with the solution of linear change. Then, for the experiment side, using diffraction in the test solution with a grating, we can get how the refractive index changes with the variation of concentration.In addition, since the refractive index is closely linked to the velocity of light in the solution, we can easily get that the speed of light increases with the concentration changes from linear, so we can indirectly measure the velocity of light in the solution. For processing the data, this study used the least square fitting, with computer programming, the figure makes a line, confirming the feasibility of this method for the measurement and solution properties,so that provides a method to measure the natures of solution.