CNR4 4-Sensor Net Radiometer – ISO 9060 spectrally flat Class A

The CNR4 is a lightweight net radiometer with all 4 sensors integrated into one instrument body. The only integrated net radiometer available with a ventilation and heating unit.


  • 5-year warranty
  • Two ISO 9060  spectrally flat Class A pyranometers
  • Two pyrgeometers
  • Optional ventilation unit
  • Integrated Pt-100 and Thermistor temperature sensors


CNR4 Net Radiometer

The CNR4 net radiometer consists of two first-class pyranometers, one facing upward, the other facing downward, and two pyrgeometers positioned similarly.

The pyranometers measure short-wave radiation. The pyrgeometer pair measures long-wave radiation.

The upper long-wave detector of CNR4 has a meniscus dome to ensure water droplets role off easily. The dome also improves the field of view to nearly 180°.

All 4 sensors are integrated directly into the instrument body in a neat compact design.

For optimal accuracy the individual sensors are calibrated individually.

CNR4 Specifications

Spectral range (50% points) 0.3 to 2.8 µm = 300 to 2800 (short wave) nm
Spectral range (50% points) 4.5 to 42 µm = 4500 to 42000 (long wave) nm
Sensitivity 5 to 20 µV/W/m²
Temperature dependence of sensitivity (-10 ºC to +40 ºC) < 4 %
Response time < 18 s
Non-linearity < 1 %
Operating temperature -40 to 80 °C
Ventilation power (of the optional CNF4 ventilation unit) 10 W