一种新型的直接日射表

RESEARCH ON A NEW KIND OF PYRHELIOMETER

由厚度８０μｍ的高度氧化的不锈钢箔片制成半径各为Ｒ１、Ｒ２的两只圆盘，其四周被焊在圆筒形的紫铜管上。当阳光同时垂直照射在该两圆盘表面并达到热平衡时，测定圆盘中心点温度Ｔ１（０）、Ｔ２（０），紫铜管温度Ｔｃ及环境温度Ｔａ，则可确定太阳直射辐射量及自然对流的换热系数。与标准级的直接日射表──美国ＴＭＩ公司的ＭａｒｋⅣ比对测试表明，其平均偏差和标准差分别小于０．３％和３．３％。试验结果证明，这是一台操作简便，价格便宜，能满足太阳辐照度常规测定的直接日射表。

pyrheliometer has been designed and constructed based on a new methodology to measure solar radiation. A disc-shaped foil made by heavily oxidized stainless steel is thermally joined to massive heat sink at its circum ference Under a steady state condition. by acquiring the temperature difference between centre.of the foil (or the heat sink) and shielded air inside the jacket. the solar radiation can be calculated. Comparison of our pyrheliometer with a calibrated TM I MARK-VI pyrheliometer shows the maximum relative deviation. the average deviation and the standard deviation are less than 6%. 0. 3% and 3 .3% respectively. The instrument is simple. inexpensive and suitable for routine measurement.