纯水细菌测定的抽样方案分析

Analysis of sampling plans of the determination of the bacterial content in pure water

以泊松分布分析了在要求细菌数少于1mL-1的纯水细菌测定中,选用采样量1mL,合格判定数为0的抽样方案,其错判概率和漏判概率都较高。提出了将细菌数≥1mL-1的纯水误判为合格的概率不超过5%的各种抽样方案,并对采样量及合格判定界限选择作了讨论。

It is analyzed that the sampling method, by which the result of bacterial test is accepted when the defect number equals zero in 1 mL water sample in which the number of bacteria is less than 1 mL-1, through Poisson distribution. And it is proved that the probability of the error determination of it is higher. The multifarious sampling methods are put forward, which can decrease the probability of the error determination of inspect result of pure water containing bacterial number ≥1 mL-1 to less than 5%. The selections of samples and principle of judge are also discussed.