单压法标准湿度发生器的设计及不确定度评定

Design and Uncertainty Evaluation of Single Pressure Method Standard Humidity Generator

标准湿度发生器在湿度量传的过程中起到重要的作用。我们设计开发的标准湿度发生器采用单压法原理,使用某单位自主研制的压缩空气干燥器、分流法湿度发生器产生的气源,通过温度、压力、饱和器系统的合理设计,能够发生(-70℃^+20℃)露点范围的湿气气源,量值范围宽,准确度高。经过冷镜式精密露点仪的验证,结果表明装置满足我国湿度一级标准的技术指标。按照不确定度评定方法评定了装置的不确定度。

This paper is mainly concerned with the ice flashover characteristic under light icing condition. According to the plate model with hydrophobic surface, the effect of impact factors, including gap length, gap position and distribution, melting time and pollution level, on the ice flashover process were analyzed. It was found that gaps due to non-uniform icing initiated the partial arcs. It was shown in U curve between gap length and ice flashover voltage, and gaps closed to the electrode were more inclined to be suffered. Melting time showed a U curve trend with the ice flashover voltage due to the variation of melting water film resistance. However, pollution level was in positive relationship with ice flashover voltage, and flashover channel were always occurred in the contamination-ice interface. Finally, according to the experiment in the artificial climate chamber, partial arcs were always initiated along the rod and lower surface of shed which could be hardly iced, and there was an decreasing trend between ice flashover voltage and pollution level.