结霜(露)对微型金属杜瓦瓶热负载测量质量的影响  

The Effect of Frosting on the Measurement of Thermal Load of Mini Metal Dewar

作　　者：李建林[1] 

机构地区：[1]昆明物理研究所,云南昆明650223

出　　处：《红外技术》2007年第12期724-729,共6页Infrared Technology

摘　　要：液氮蒸发测量原理进行热负载测量的误差较大,传统天平、计时器人工测量热负载符合检验A级要求时,仅能满足微型金属杜瓦瓶热负载技术指标为(150±40)mW的测量要求。通过分析结霜(露)和冷氮气对测量的影响,推导和图示了产生的测量误差,对重复性测量观测值进行统计分析,讨论了热负载相对误差,评定热负载、液氮质量和结霜(露)质量的测量不确定度。当热负载技术指标为(150±15)mW,根据检验A级测量能力指数4的要求,测量扩展不确定度U=1.88mW,置信水平为95.45%,标准不确定度u(QM)=0.94 mW。现有传统天平、计时器人工测量热负载的测量能力明显不足,不满足(150±15)mW测量准确度的要求。Thermal load is a comprehensive index that can describe a mini metal Dewar＇s heating isolation. The LN2 evaporating measurement will cause remarkable error. Manual measuring with traditional balance and timer can only reach （150±40）mW which is only a lower degree of test grade A for a mini metal Dewar＇s thermal load measurement specification. The effect of frosting and cold N2 on the measurement was analysed, the measurement error was calculated and graphed, and the repeatability of the measurement value was counted. The relative error for thermal load and the measuring criterion of frosting mass were discussed. The measurement uncertainty of thermal load, LN2 mass and frosting mass was assessed. According to the demand of measurement ability index 4, test grade A, if the technological specification index is （150±15）mW, the expanding uncertainty of measurement will be U=1.88 mW, the reliability will be 95.45%, and the standard uncertainty will be U（QM）= 0.94 mW. Obviously the manual measurement with existing balance and timer can not satisfy the demand of precision of （ 150±15）mW.

关 键 词：微型金属杜瓦瓶 热负载 测量不确定度 测量误差 

分 类 号：TB663[一般工业技术—制冷工程] TN215[电子电信—物理电子学]