SGR4 Pyrgeometer
The SGR4 is Kipp & Zonen's top-tier pyrgeometer for measuring downward longwave radiation, with an RS-485 Modbus interface and an amplified analogue output.
- Supply
- 5 to 30 VDC
- Spectral range
- 4.4 to 50 µm (4400-50000 nm)
- Response time (95%)
- 18 s

Overview
In detail
How it works
The SGR4 measures downward longwave radiation across a 4.4 to 50 micron spectral band, with temperature-corrected measurement data and improved response time compared to earlier pyrgeometers. Long-wave net and downward radiation values are available directly over Modbus.
Connectivity
The sensor provides a 2-wire RS-485 Modbus digital interface alongside an amplified analogue output (4-20mA or 0-1V depending on version).
Power
A wide 5 to 30 VDC supply range simplifies integration into meteorological and solar energy monitoring stations. The SGR4 is robust and carries a 5-year warranty.
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Specifications
Technical specifications
- Spectral range
- 4.4 to 50 µm (4400-50000 nm)
- Response time (95%)
- 18 s
- Operating temperature
- -40 to +80°C
- Supply voltage
- 5 to 30 VDC
- Analogue output
- 4-20mA / 0-1V (version dependent)
- Digital output
- 2-wire RS-485 Modbus
- Field of view
- 180°
- Non-linearity
- <1%
- Window heating offset
- <4 W/m²
- Zero offset B
- <2 W/m²
- Temperature dependence of sensitivity
- <1% (-20°C to +50°C)
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