Research On The Sampling And Grading Theory Of The Defects In The Electronic Testing For Raw Silk

The electronic testing for raw silk is the direction of the development of current raw silk test in China. In order to construct a scientific and rational system that consist of related test equipments, experimental methods and grading standards in the electronic testing for raw silk, research on the problem about the sampling and grading method of the defects in the electronic testing for raw silk is an important basic task. In this topic, by testing fifteen batches of raw silk in the current test and electronic test for raw silk at the same time, the correlation coefficients among size deviation, maximum size deviation, evenness change 2nd degree, cleanness, neatness as determined by the current test and three types of slubs, thick and thin place as evaluated by the electronic test, were analyzed and discussed. Based on the data obtained from the electronic testing for raw silk, the characteristics of distribution types of the defects were discussed by using frequency discussion as well as aggregation indexes, and the fact that negative binomial distribution can be used to similarly describe the distribution of various types of defects was confirmed, and the correlations among the three kinds of slubs were analyzed. According to the analysis of determining the optimal sampling quantities for three types of slubs, thick and thin place in theory. It put forward that whether the determined sampling quantities meet to the requirements of the highest raw silk or not should be firstly taken into account, and the accuracy and cost of testing the big defects in high-grade raw silk should be coordinated when determining the optimal sampling quantities. With regard to the research on the grading method of the defects ,on the conditions that the distributions of the average of the sampling samples of the slubs and the thick and thin places both similarly obey normal distribution according to comprehensive assessment, the right grading rate and the probability of the difference between two spot tests about the two defect targets of raw silk in the electronic testing were deduced, moreover, the division method of the grade interval was analyzed and the approximate formula of each grade interval limits was given. Meanwhile, the above-mentioned theory is confirmed and the application analysis is discussed by simulation and examples. The results of the research provide basis for establishing the grading standards for raw silk.