Study on the influence of testing frequency and sample quality on the whiteness test of ramie fibers
GB/T 5885-1986"Test Method for Brightness of Ramie Fiber"only requires the sample to be placed in the sample box without exposing the white background,without specifying the specific mass of the sample.The amount of test sample mass affects the thickness of the sample,which in turn affects the reproducibility of the whiteness test results,resulting in weak comparability between results.In addition,the standard requires a testing frequency of 50 times,and excessive measurement times can affect the efficiency of testing the whiteness of ramie fibers.Therefore,this article calculates the precision of the whiteness test results of ramie fiber samples with masses of 0.6 g,0.7 g,0.8 g,0.9 g,etc.It is found that after the sample weight is greater than 0.6 g,the precision of the test is much lower than 5％,and the reproducibility is good.Therefore,the sample weight can be set at 0.6 g;A dif-ferential analysis was conducted on the test results of the same ramie fiber sample after 10,20,30,40,50 different test cycles.It was found that there was no significant difference in the test results after more than 20 test cycles.Therefore,the test cycle can be set as 20.Therefore,this article suggests that the standard for testing the whiteness of ramie fibers should set the test weight to 0.6 g and modify the number of tests to 20.
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