|
|
| About Freeword: "weight loss" |
| List | Prev. | Next |
| PDF : |  25110713.pdf |
| title(En) : | Studies on Testing Method for Wear Resistance of Woods by Taber Abraser.II. Statistical characteristics of Taber's sandpapers accepted by concerned standards |
| author(En) : | Kiyoyasu Yamada, Hiroyuki Hayashi |
| information : | Mokuzai Gakkaishi 25(11), 713-718 (1979) |
| assort : | Original Article |
| summary(En) : | Statistical characteristics of Taber's sandpapers accepted by concerned standard specifications are discussed. Weight loss of Taber's standard zinc plate for 500 revolutions is used as indication for abrasive quality of sandpapers. The results are as follows: 1) In advance of discussion the normality of distribution of test results was inspected. As the results of comparison of the difference between frequency of test results and of theoretical probability with values from χ2-distribution, the normality was recognized highly significant. 2) Mean value of test results (x*1) was 129.7mg, and standard deviation (Σ) was 12.8mg. 3) American NEMA standard is regarded as original of concerning standards that specify inspection method of Taber's sandpaper. For the purpose of comparing NEMA with domestic standards statistical characteristics of the sandpapers accepted by NEMA was clarified on x*1 and Σ obtained above for each case of certifying mean value of lot and fraction defective of lot when sampling size n changed from 2 to 4. In practice NEMA fixes n as 4. In this case Σmax of acceptable lot was 16.0mg. 4) Every concerned standard spesifies 3 or more as n. From the view of producer's risk, the propriety of this definition was confirmed on the basis of test results. 5) On the whole sampling plans of domestic standards had a tendency to lean toward more tightened inspection than NEMA, and some of them were somewhat irrational. กกกก*1 bar over x |