The paper aims to determing the BOD_5 in water sample in accordance with GB7488 - 87. The uncertainty produced by random effect and system effect is estimated and the uncertainty of the determination of BOD_5 is evaluted.

• 依据GB7488-87标准的方法,测定了水样的生化需氧量BOD_5,估算了测试过程中的随机效应和系统效应所产生的不确定度分量,最终评定了生化需氧量浓度的测量不确定度。