确定混合料取样样本容量的模型与方法

Model and Method for Determining Sample Capacity of Mixture

针对搅拌设备拌合料试验检测中总体均值估计的样本容量问题,采用区间估计理论分别就总体方差已知和总体方差未知2种情况建立区间估计表达式,得出区间估计精度与样本容量之间的关系模型,并提出基于统计分析技术的样本容量确定方法。对于未规定估计精度要求的试验数据,样本容量宜取3~5个,取均值估计总体平均值,不仅能够保证较高的检测精度,而且可以提高工作效率、减小试验误差、降低作业成本。

Aimed at the problem of determining the sample capacity of estimation of population mean during the tests on the mixture, the theory of confidence interval estimation was applied to establish the interval estimation expressions for both situations whether the population variance was given or not. The relational model between the precision of interval estimation and the sample capacity was obtained, and a method based on statistic analysis techniques for determining the sample capacity was proposed. The findings show that it is better to select 3 to 5 samples for the test data without specified estimation precision. Using the mean value of the sample capacity to estimate the population mean could not only guarantee higher detection accuracy, but also improve work efficiency and reduce test errors and operational costs.