精密太阳辐照度计关键技术介绍:
精密太阳辐照度计的精密辐射传感器是世界气象组织(WMO)一级辐射表,用于测量太阳和天空辐射,适应很宽的波长范围。它由一个组合热电堆电路组成,可以很好的抵抗机械震动和打击。传感器的接收器有一层Parson黑漆,底部为一个半球型玻璃顶罩。玻璃半球使用的是WG295玻璃,对于0.285-2.8um的波长具有非常好的透光性,而且能量传输非常的均一。对于一些特殊的应用,其它的schott玻璃和Infrail II石英玻璃也可以使用。该公司的该是世界气象组织(WMO)的一级辐射表,设计用于测量全球太阳总辐射。传感器包括一个水平调节装置,一个水平泡和水平调节螺栓以及一个干燥器。传感器的外壳为铸造青铜体,外层为白色珐琅遮蔽盘,传感器的标定可溯源WRR,含温度补偿曲线。
特点:
量化太阳对地面的可变辐射、计算太阳辐射通量
技术参数:
灵敏度:大约9um/Wm-2
阻抗:大约650欧姆
温度依赖性:+-1%@-20-40
线性:+-0.5%@0—2800Wm-2
相应时间:1s(1/e信号)
余弦响应:+-1% @0-70度天顶角;+-3% @70-80度天顶角
机械振动:最大20 g's无损坏
标定:半球积分; 尺寸:直径5.75英尺,高度3.75英尺; 重量:7磅
精度:标定的绝对精度为+-3—4%,标定的相对精度大约为+-2%。真实的余弦响应背离是由于标定的大绝对误差。
现场的使用性能
由于该的灵敏度长时间使用后会有所降低,因此推荐每年都进行一次标定。标定一个辐射传感器的精度,好的方法是测量来自一个绝对腔体表的直接光束辐射和散射辐射,黑白辐射表需要一个遮蔽盘。直接辐射在地平面以上发生,散射辐射值可以增加获得总辐射的最好评估。
There are two generally accepted Classification Systems used for Pyranometers. ISO classifies pyranometers as a “Secondary Standards”, “First Class” or “Second Class” while WMO uses “High Quality”, “Good Quality” and “Moderate Quality”.
The Precision Spectral Pyranometer, is classified as a ISO Secondary Standard or WMO High Quality Pyranometer.
· Classification: ISO Secondary Standard Pyranometer / WMO High Class
· Response time: 1 second (1/e signal).
· Response Time (95%): 10-15 seconds
· Zero Offset to 200 Wm-2 net radiant loss to sky: 4-6 Wm-2
· Zero Offset to 5° C/hr change in ambient temperature: 1-2 Wm-2
· Resolution: < 1 Wm-2
· Non-Stability: <0.5% / yr (typical)
· Non-Linearity: ±0.5% from 0-2800 Wm-2
· Directional Response: < 10 Wm-2
· Spectral Selectivity: 1%
· Temperature Response: ±1%
· Tilt Response: < 0.5%
· Achievable Uncertainty (Hourly): 1-2 %
· Achievable Uncertainty (Daily): 1-2 %
· Suitable Application: Working Standard or Network Measurements
· Sensitivity: approx. 9 µV/Wm-2.
· Impedance: approx. 650 Ohms.
· Temperature Dependence: ±1% over ambient temperature range -20 to +40°C
· (temperature compensation of sensitivity can be supplied over other ranges at additional charge).
· Linearity: ±0.5% from 0 to 2800 Wm-2.
· Cosine:
o ±1% from normalization 0-70° zenith angle;
o ±3% 70-80° zenith angle.
· Mechanical Vibration: tested up to 20 g's without damage.
· Calibration: integrating hemisphere.
· Size: 5.75 inch diameter, 3.75 inches high.
· Weight: 7 pounds.
· Orientation: Performance is not affected by orientation or tilt.
· A calibration certificate traceable to the World Radiation Reference and a temperature compensation curve is included.