The Measurement Method Of Newton's Rings Stress Based On MSP430

Since the advent of Newton's rings, there are many scholars who employ themselves in the experiment exploration. Some scholars take how to improve the precision of measurement as the research focus, while others use the principle applied to other areas. However, it is easy to see that no scholars analyze the degree of tightness of screw on the influence of experimental error, not to mention how remove the screw on the influence of experimental error. Based on the research status at home and abroad, two purposes of the research were put forward: removing the screw on the influence of experimental error, in-depth analysis of the measuring stress by optical interference method and summarizing the application conditions of the theory.The main research is as follows. Firstly, the thorough analysis of the stress and deformation of plane convex and flat glass has been carried out, and the Newton's ring stress measurement device was designed combing with the characteristics of the shape structure of stress sensor. Secondly, A measurement circuit is designed based on MSP430F149, however, the circuit can't meet the requirements of experiment because of the accuracy of measurement, but when the existing electronic balance were reformed through analysis of the operation principle of it, the accuracy of measurement met the requirement. Thirdly, by use of building platform, a large number of experiments show that the more tight of the screw, the greater of the radius of curvature. The relations between the pressure and radius of curvature were analyzed by MATLAB, and it was proved to be the linear correlation. The thought of stress correction was put forward based on the fitting formula, and the experimental results show that pressure correction can eliminate the tightness of screw on the influence of experimental error, after correction of experimental error less than 0.6%. Fourthly, theory formula by according to the theory of plate theory was deduced combining with the Newton's rings device which was modified, on this basis, the formula had been corrected and a lot of experiments had been done for verifying the correctness of the formula and exploring the application conditions of it.