Kipp & Zonen 的長波輻射計可長時間在任何天氣狀況下良好使用。帶有防水插頭的信號電纜便于安裝維護。鑲嵌其上的白色太陽遮擋環，使傳感器熱化效應降到。

CGR4是當前可以得到高質量的科學測量數據的輻射計。獨特的半月板圓頂設計可以提供180度的測量視角，有很好的余弦響應。圓頂外部的堅硬涂層不僅有利于光譜響應而且可保護硅表面。圓頂設計和優良的耐熱材料使儀器本身削減了溫度變化及頂部陰影造成的影響。CGR4可以通過添加CV2強之通風罩來提高其測量的準確性。

CGR 4 pyrgeometer is an instrument for the highest quality scientific measurements. The specially designed meniscus dome provides a 180o field of view with negligible directional response error. A hard-carbon coating on the outside of the dome smoothes the spectral response and provides extra protection to the silicon surface. The excellent thermal stability of the dome construction and coupling to the instrument body eliminates the need for dome temperature measurements or dome shading. CGR 4 can be fitted with the CVF 3 ventilation unit to further improve its performance.

A waterproof socket is fitted for the signature yellow signal cable, which is available in a range of lengths pre-wired to the waterproof plug.

The integral bubble level is raised to the top of the housing and can be viewed without removing the redesigned snap-on sun shield, which also covers the connector. The connector with gold-plated contacts allows for easy exchange and re-calibration. The drying cartridge is now a screw-in type that can be simply removed using a coin, for changing the desiccant that is supplied in convenient refill packets.

Product Specification
Spectral range 4500 to 42000 nm
Sensitivity 5 to 10 μV/W/m2
Response time 18 s
Window heating offset < 4 W/m2
Zero offset B < 2 W/m2
Temperature dependence of sensitivity (-20 oC to +50 oC) < 1 %
Operating temperature range -40 to +80 °C
Net irradiance range -250 to + 250 W/m2
Field of view 180 °
Non-linearity < 1 %