凯尔文效应影响露点仪测量准确度的分析

The Analysis of Accuracy that KaiErWen Effect Affects the Instrument of Dew Point

露点仪测量的是样本空气等压降温至开始有微小露滴凝结时的温度,即样本空气对于弯曲水面达到饱和时的温度,称为结露温度。由于凯尔文效应,使得纯水曲面的饱和水汽压与纯水平面饱和水汽压有一定的差异,从而导致结露温度低于实际露点温度。本文编程计算了同一样本的结露温度与实际露点温度的偏差,结果表明凯尔文效应造成的露点仪测量误差约为0.1℃,并讨论了减小误差的方法。

What the instrument of dew point measures is the temperature that sample air cools to the time when small dew drop condenses under equal pressure. Sample air reaches the temperature in saturation for curved water surface , is called as close dew temperature. Because of KaiErWen effect, there is certain discrepancy between the saturation steam press for pure horizontal surface and the one for pure water curved surface, which causes close dew temperature to be lower than the actual temperature of dew point. This paper has programmed and calculated the deviation between the actual temperature of dew point and the close dew temperature of the same sample, and has discussed the methods decreasing error. The result has explained that the measuring error is approximately 0.1℃by KaiErWen effect while measuring dew point with the instrument of dew point.