SN/T 5243-2020Inspection method for lint content of imported and exported washed goat hair (English PDF)

6.1 Manual inspection method

6.1.1 From the samples prepared after calculating the coefficient, randomly select 2 test samples, each with a mass of 5 g, accurate to 0.01 g.

6.1.2 The number of the test sample after the weighing is placed in a container, and the hair, dander and other impurities other than velvet are picked out with tweezers and weighed.

The amount of velvet is accurate to 0.01 g.

6.2 Instrumental analysis method

6.2.1 From the samples prepared after calculating the coefficient, randomly select 2 test samples, each with a mass of 100 g, accurate to 0.01 g.

6.2.2 Put the weighed test sample numbers into the goat hair lint analyzer, separate the lint from the lint, and take it out of the lint collection box After removing the wool, soil and impurities, weigh the amount of wool to the nearest 0.01 g.

7.1 Result calculation

The velvet content rate is calculated according to formula (2).

H-velvet content, %;

K-coefficient, determined by formula (1);

m3-the mass of the sample, in grams (g);

m4-the mass of down fiber, in grams (g).

7.2 Results presentation

7.2.1 In the above two repeatability tests, the absolute value of the difference between the results of the fleece rate is not greater than the value of r (1.78), and then the two average values are taken as the final result.

7.2.2 When the absolute value of the difference between the two test results is greater than the value of r (1.78), the third sample should be tested additionally. If the three repeatability tests result If the absolute value of the difference is less than the critical range Cr R95 (3), the final result shall be the average of the 3 test results.

7.2.3 When the range of the three test results is greater than the critical range Cr R95 (3), the fourth test result shall be additionally tested. If 4 repetitive tests the absolute value of the difference between the test results is less than the critical range, and the final result of Cr R95 (4) is the average of the four test results. When 4 samples contain velvet If the absolute value of the rate is greater than the critical range Cr R95 (4), the final result is the median of the 4 test results.

The above critical range is calculated according to formula (3).

7.2.4 Precision

7.2.4.1 Repeatability. In the same laboratory, the same operator uses the same equipment, according to the same test method, and in a short time the absolute difference between the two independent test results obtained by the same object under mutual independent testing shall not be greater than r=1.78.

7.2.4.2 Reproducibility. In different laboratories or in the same laboratory, different operators use different equipment, according to the same test method Method, the absolute difference between the two independent test results obtained by testing the same object against each other is not greater than R=2.27.