First class pyranometer ISO9060
PCTRA056 pyranometer is intended for solar radiation measurement on a plane/level surface (Watt/m²). The radiation measured is the sum of direct sun and of diffuse irradiance (global radiation).
PCTRA056 uses a ISO 9060 First class pyranometer and it complies with WMO publication “Guide to meteorological Instruments and Methods of Observation”, 5th edition (1983).
The pyranometer is based on a thermopile sensor. The sensing surface of the thermopile is coated with an opaque black paint providing a flat spectral response for the full wavelength range. The spectral range of the pyranometer is determined by the transmission through the glass dome K5 type.
The irradiance energy is absorbed by the blackened surface of thermopile providing a temperature difference between the centre of the sensor (hot junction) and the body of pyranometer (cold junction). This difference is then converted to a voltage according to the Seeback effect.
PCTRA056 has two domes with 50 and 30 mm external diameter to guarantee correct thermal insulation from wind and to reduce sensitivity to thermal radiation. The dome protects the thermopile from dust which could modify spectral sensitivity. PCTRA053 is then provided with a bubble level for the correct levelling of the sensor.
To avoid condense formation on the inner surface of the dome, moisture absorbing silica-gel is put inside the pyranometer.