对烧结金属材料在开孔率测定过程中的不确定度来源进行了分析，并对开孔率测定结果的不确定度进行了评定。结果表明：烧结金属材料开孔率测定的不确定度来源主要包括称量试样在空气中的质量、在水中完全浸润的质量、在空气中被水完全浸润的质量引入的不确定度以及数值修约等；某烧结金属转子衬套开孔率测定结果的不确定度报告为K=26.4%，U=0.2%，k=2（K为开孔率，U为扩展不确定度，k为包含因子）。

The uncertainty sources in measurement of porosity rate of sintered metal materials were analyzed, and the uncertainty of the measurement results was evaluated. The results show that the uncertainty sources in measurement of porosity rate of the sintered metal materials mainly come from weighing sample's mass in air, sample's mass in water with water completely be soaked in and sample's mass in air with water completely be soaked in, data rounding and so on. The uncertainty report of measuring porosity rate of a sintered metal rotor bush was as following:K=26.4%,U=0.2%,k=2 (K being the porosity rate, U being the extended uncertainty, and k being the coverage factor).