汽轮机油中水分测定的不确定度讨论

Discussion on Uncertainty of Moisture Determination in Turbine Oils

水分对汽轮机油的危害很大,会降低汽轮机油的润滑性能和防锈性能,与氧化物形成酸性物质,加剧汽轮机油氧化,造成添加剂流失和分解等。因此测定汽轮机油中的水分是一项十分重要的工作。以测定L-TSA46号汽轮机油中水分(水分质量分数32μg/g)为例,对卡尔费休库仑滴定法测定水分的不确定度来源进行了分析和评估。当置信水平为95%时,计算出了卡尔费休库仑滴定法测定水分的扩展不确定度(约5.7μg/g)。正确评估测定过程中的不确定度是提高水分测定准确性的关键。

Moisture had big harm to turbine oils and it would reduce the lubricity and anti-rust performance of turbine oils.Moisture and oxide formed acidic substances ,and aggravated the oxidation of turbine oils,resulted in the loss and decomposition of additives.So it was a very important work to determine the moisture in turbine oils. To determining the moisture （mass fraction of 32 μg/g） in L-TSA46 turbine oils as an example, the sources of uncertainty in the determination of moisture in the Karl Fischer Coulometric titration method were analyzed and evaluated.When the confidence level was 95%, the expanded uncertainty （about 5.7 μg/g） of moisture was calculated by the Karl Fischer Coulometric titration method.Correct assessment of the uncertainty in the measurement process was the key to improve the accuracy of moisture determination.