Sharing calculation methods for falling weight fabric tear tester test results

The falling weight fabric tear tester is a special instrument for testing the tear strength of fabrics. The tear strength of double tongue samples is a common test item. This instrument can test the force required for a variety of sheet or film samples to expand to a specified length under a specified load and specified crack. It can detect the tear resistance under 200-32,000 MN impact force, and the impact force corresponds to the specific drop weight. The instrument cuts a tongue-shaped opening in the sample, then measures tear strength as the incision enlarges. The instrument design is convenient and flexible and can be used for a variety of tests on light and heavy samples.

Now let\'s understand the method of calculating the test results of this test item:

1. Savestrated from the recording paper The tear strength is calculated manually on the strength-elongation curve.

2. Divide the peak curve: divide it into four zones from peak start to peak end. The regional peaks are discarded and the remaining three regions are selected and marked with two peaks and two weak peaks in each region. Note: When calculating and selecting a peak according to the above regulations, the value of the strongly descending section on both sides of the peak must exceed the value of the ascending section by at least 10%, otherwise it will not should not be selected. For high-density fabrics, the feeding speed of the recording paper should be slowed down until the maximum value of the design is clear.

3. Calculate the arithmetic average of the 12 peaks in each sample, the unit is N. If necessary, the sum of the small peaks in these three areas canbe recorded. Note: Manual calculation can only take into account a limited number of peaks to save time. It is recommended to use electronic means to calculate all peaks.

4. Calculate the total arithmetic average of the tear strength of the samples in the same direction, expressed in N, and retain two significant figures.

5. If necessary, calculate the coefficient of variation with an accuracy of 0.1% and the 95% confidence interval of the average value calculated based on the average value of previous samples, rounded.

6. Divide the peaks into four equal regions, remove the peaks from the regions, and save all the peaks from the remaining three regions.

7. Use all the maximum values ​​recorded in step 6 to calculate the arithmetic mean of the tear strength of the sample.

8. Use the average value of eache sample to calculate the total arithmetic average of the tear strength of all samples in the same direction, expressed in N, and retain two significant figures. .

9. If necessary, calculate the coefficient of variation with an accuracy of 0.1% and the 95% confidence interval after rounding the mean value calculated based on the annual average of 7 samples.

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