CGR3 Pyrgeometer

Low cost pyrgeometer with digital interface for accurate routine measurements in many applications.


The CGR3 is a pyrgeometer, designed for meteorological measurements of downward atmospheric long wave radiation. The CGR3 provides a voltage that is proportional to the net radiation in the far infrared (FIR). By calculation, downward atmospheric long wave radiation is derived. For this reason CGR3 mbodies a temperature sensor. The CGR3 uses a specially designed silicon window. On the inside a solar-blind filter blocks solar radiation. The CGR3 data represents the radiation exchange within the whole hemisphere. This is because the reference CGR3 is calibrated outdoors with respect to a reference CG4, which has a 180 degrees field of view.


Spectral range (50% points) 4.5 to 42 µm = 4500 to 42000 nm
Sensitivity 5 to 15 µV/W/m²
Response time < 18 s
Window heating offset < 15 W/m²
Zero offset B < 4 W/m²
Temperature dependence of sensitivity (-10 ºC to +40 ºC) < 5 %
Operational temperature range -40 to +80 °C
Net irradiance range -250 to +250 W/m²
Field of view 150 °
Non-linearity < 1 %