Kipp & Zonen ISO/IEC 17025 Accredited Calibration Service

Kipp & Zonen Calibration Service

We are proud to announce that the radiometric calibration laboratory at our factory in Delft, the Netherlands has been accredited to the EN ISO/IEC 17025 quality management standard for the sensitivity calibration of our pyranometers and pyrheliometers.

How We Calibrate

Our pyranometer calibrations for many years have been carried out to the international standard ISO 9847:1992 ‘Calibration of Field Pyranometers by Comparison to a Reference Pyranometer’. We use method IIc, for direct beam indoor calibration, as described in Annex A ‘Calibration Devices Using Artificial Sources’. Our equipment and method are specifically referred to in Annex A.3.1 as the “Kipp & Zonen Device and Procedure”. We have improved this since the original 1992 description.

ISO 9847 requires that reference pyranometers are calibrated outdoors to ISO 9846:1993 by comparison to a reference pyrheliometer for direct radiation and a reference shaded pyranometer for diffuse radiation. The global radiation is calculated form these values and the solar zenith angle, and we do this using the alternating sun-and-shade method.

We calibrate pyrheliometers using our own indoor procedure that has been developed and refined over many years. The Accreditation Council has determined that this is a valid and accurate method.

All our pyranometer and pyrheliometer calibrations are traceable to the World Radiometric Reference (WRR) which represents the SI units of irradiance and itself has an uncertainty of ± 0.3% at the 95% confidence. The WRR is located at the World Radiation Centre (WRC) in Davos, Switzerland and WRC is operated by the Physikalisch-Meteorologisches Observatorium Davos (PMOD) by appointment of the World Meteorological Organisation (WMO).

Not All Accredited Laboratories Are The Same

One of the most important parameters on any ISO/IEC 17025 accreditation certificate is the Calibration and Measurement Capability (CMC) at the 95% coverage / confidence level. This is the best calibration uncertainty that can be achieved, and it varies from laboratory to laboratory depending upon the processes and traceability used.

Kipp & Zonen is accredited for sensitivity calibration with excellent CMC values of 0.9% for pyranometers and 1.1% for pyrheliometers. The individual calibration uncertainty depends upon the model of radiometer and its performance characteristics, but the accredited CMC’s demonstrate the high quality of our methods and procedures.