SMP 21 Pyranometer

Pyranometer with digital interface for meteorological networks, reference measurements in extreme climates, polar or arid.


The SMP21 is a secondary standard pyranometer that combines the sensor technology from the CMP21, has the RS-485 Modbus interface, analogue output and low maintenance.

The SMP21 has Modbus® RTU interface, amplified analogue output, improved response time and individual temperature corrected measurement data. The SMP21 is supplied with individual measured cosine response data. The wide and low power supply range from 5 to 30VDC makes integration in meteorological and solar energy stations easy. The SMP21 is protected against over voltage, reversed polarity and short circuiting.


Spectral range (50% points) 285 to 2800 nm
Sensitivity 7 to 14 µV/W/m²
Response time 5 s
Zero offset A < 7 W/m²
Zero offset B < 2 W/m²
Directional response (up to 80° with 1000 W/m² beam) < 10 W/m²
Temperature dependence of sensitivity (-20 ºC to +50 ºC) < 1 %
Operational temperature range -40 °C to +80 °C
Maximum solar irradiance 4000 W/m²
Field of view 180 °