Our reference radiometers are primarily used in the fields of meteorology and climatology, as well as solar energy. Our high-precision reference radiometers are used to calibrate field instruments for solar irradiance measurements, such as pyranometers and pyrheliometers.
These instruments require regular calibration or validation. This ensures the accuracy of the measurements and their traceability to the applicable reference standard. Regular calibration keeps measurement uncertainty low and allows comparison with other measurements taken elsewhere or at an earlier time.
The mandatory reference standard for solar irradiance is the World Radiometric Reference (WRR) an artefact-based standard hosted at the World Radiation Centre (WRC) in Davos. Our radiometers represent WRR and are a means of transferring the standard in order to ensure traceability to WRR.
Measurement and calibration procedures as well as instrument classifications for solar irradiance measurements are described in the WMO-CIMO Guide and within several standards of ISO. While the WMO-CIMO Guide focuses more on meteorological measurements, the ISO standards focus more on solar energy applications.
Pyrheliometer comparisons are an important way of ensuring traceability. Several such comparisons are held each year, where users gather with their equipment to compare, validate and calibrate their reference radiometers.
The most significant of these is the International Pyrheliometer Comparison (IPC), which takes place at the World Radiation Centre (WRC) in Davos every five years. During the IPC, the World Radiometric Reference (WRR) is validated and the world standard is redistributed to all participants.
Several regional comparisons, held at various locations around the world, also redistribute the standard and allow IPC participants to validate their reference radiometer calibration against other regional references.
Besides the validation and calibration of pyrheliometers, these events are supporting the build-up of knowledge and the exchange within the solar radiation community. Davos Instruments frequently participates in these events to ensure the high quality of its instruments and support its customers.
Davos Instruments is pleased to announce its participation in the following events:
14th WMO International Pyrheliometer Comparisons IPC-XIV
22. September – 10. October 2025
PMOD/WRC in Davos, Switzerland