Pyranometers
Pyranometers (global radiation sensors) measure global radiation. They are also used as reference instruments due to their measurement precision.
The use of this sensor is crucial for measurements with solar-powered applications. It is advisable to use only classified and calibrated pyranometers to ensure accurate results. Adjustable feet and a level allow easy horizontal adjustment.
Specification of Solar irradiance sensors according to ISO 9060
Pyranometers are classified according to ISO 9060 standard: "Solar energy - Specification and classification of instruments for measuring hemispherical solar and direct solar radiation". The standard is officially approved by the World Meteorological Organization (WMO). The standard specifies three classes:
- Class A: Scientific quality and highest accuracy
Applications: Meteorology (BSRN Network); Testing in PV , CPV and CSP - Class B: Good quality
Applications: Measurements for hydrology networks and greenhouse climate control - Class C:Medium quality
Application: Economic solution for routine measurements in weather stations and field testing
| ISO 9060:2018 PYRANOMETER SPECIFICATIONS | CLASS A | CLASS B | CLASS C |
| Old ISO 9060 Pyranometer Specifications (before 2018) | Secondary Standard | First Class | Second Class |
| Response time: time to reach 95% response | < 15 s | < 30 s | < 60 s |
| Zero-offset: Offset-A: response to 200 W/m² net thermal radiation, ventilated Offset-B: response to 5 K/h change in ambient temperature |
+ 7 W/m² ± 2 W/m² |
+ 7 W/m² ± 2 W/m² |
+ 7 W/m² ± 2 W/m² |
| Non-stability: % change in responsivity per year | ± 0.8% | ± 1.5% | ± 3% |
| Non-linearity: % deviation from responsivity at 500 W/m² due to change in irradiance from 100 ... 1000 W/m² |
± 0.5% |
± 1% | ± 3% |
| Directional response (for beam irradiance): the range of errors caused by assuming that the normal incidence responsivity is valid for all directions when measuring from any direction, a beam radiation whose normal incidence irradiance is 1 000 W/m² | ± 10 W/m² | ± 20 W/m² | ± 20 W/m² |
| Spectral selectivity: % deviation of the product of spectral absorbance and transmittance from the corresponding mean, from 0.35 ... 1.5 μm | ± 3% | ± 5% | ± 10% |
| Temperature response: % deviation due to change in ambient within an interval of 50 K, (e.g. - 10 ... + 40 °C typical) | 2% | 4% | 8% |
| Tilt response: % deviation in responsivity relative to 0 ... 90° tilt at 1 000 W/m² beam irradiance | ± 0.5% | ± 2% | ± 5% |
|
Achievable uncertainty (95% confidence level) |
3% |
8% |
20% |