2x21/2的渐近分布和失效率试验国际标准的改进

The Asymptotic Distribution of （2x2）1/2 and the Improvement of International Standard of the Failure Rate Test

国际通用的IEC409标准规定了电子元器件抽样寿命截尾试验检验结果应该用60%或90%置信度的失效率单侧置信估计值表示。但是,用不同置信度的失效率表示的两比产品,不能直接地准确比较其可靠性的优劣。而且90%置信度的抽样检验特性很不合理。本文介绍了作者针对此问题所做的下述工作:(1)证实了((2x)~2)^(1/2)渐近地服从N((2n-4/3)^(1/2),1),这个结果远比著名的经典结论N((2n-1)^(1/2),1)精确。(2)在此基础上找到了勿须查表的元器件失效率单侧置信估计公式。该公式简单,精确,易于普及应用,并适用于定时、定数截尾和有替换与无替换多种试验。(3)建议改进国际标准IEC409文件,将可靠性试验的置信度统一为50%。

The international used IEC Standard Publication 409 stipulate that the testing result of the cut tail life test for electronic components(or parts) shoud be expressed with 60% or 90' confidence level failure rate of one-sided confidence estimate value.But two group products can not to be compared between them of they used the different confidence level failue rate.And the 90% confidence level sampling examination is not reasonable.This paper introduce author's work on above problem:(1) Proving that (2x^2)^(1/2) asymptotically obeys N((2n-4/3)^(1/2),1).This result is much more accurate than the famous classical result N((2n-1)^(1/2),1). (2)On above base finding a formula to estimate the failure rate of the one-sided confidence of the conponents (or parts).This formula is simple,accurate and easy to be widely used in a lot hind of experiments in factory (Include fixed time,fixed number,replacing,and non-replacing experiments).(3) Suggesting to improve the international standard IEC 409 to adopt the unity confidence level 50% in reliability testing.