Intercomparison of erythemal broadband radiometers calibrated by seven UV calibration facilities in Europe and the USA G. Hülsen1, J. Gröbner1, A. Bais2, M. Blumthaler3, P. Disterhoft4, B. Johnsen5, K. O. Lantz4, C. Meleti2, J. Schreder6, J. M. Vilaplana Guerrero7, and L. Ylianttila8 1Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center, Dorfstrasse 30, 7278 Davos Dorf, Switzerland 2Aristotle University of Thessaloniki, Laboratory of Atmospheric Physics, Campus Box 149, 541 24 Thessaloniki, Greece 3Innsbruck Medical University, Division for Biomedical Physics, Müllerstr. 44, 6020 Innsbruck, Austria 4National Oceanic and Atmospheric Administration, Central UV Calibration Facility, 325 Broadway, 80305 Boulder, CO, USA 5Norwegian Radiation Protection Authority, Grini Naeringspark 13, 1361 Osteras, Norway 6CMS Ing. Dr. Schreder GmbH, Eggerstrasse 8, 6322 Kirchbichl, Austria 7Instituto Nacional de Técnica Aerospacial, Estación de Sondeos Atmosféricos El Arenosillo, 21130 Mazagon, Spain 8STUK, Radiation and Nuclear Safety Authority, Non-Ionizing Radiation Laboratory, P.O. Box 14, 00881 Helsinki, Finland
Abstract. A bi-lateral intercomparison of erythemal broadband radiometers was performed
between seven UV calibration facilities. The calibrations provided by the
instruments owners were compared relative to the characterisation and
calibration performed at PMOD/WRC in Davos, Switzerland. The calibration
consisted in the determination of the spectral and angular response of the
radiometer, followed by an absolute calibration performed outdoors relative
to a spectroradiometer which provided the absolute reference.
The characterization of the detectors in the respective laboratories are in
good agreement: The determinations of the angular responses have deviations
below ±4% and the spectral responses agree within ±20%. A "blind"
intercomparison of the erythemally weighted irradiances derived by the
respective institutes and PMOD/WRC showed consistent measurements to within
±2% for the majority of institutes. One institute showed slightly
larger deviation of 10%. The differences found between the different
instrument calibrations are all within the combined uncertainty of the
Citation: Hülsen, G., Gröbner, J., Bais, A., Blumthaler, M., Disterhoft, P., Johnsen, B., Lantz, K. O., Meleti, C., Schreder, J., Vilaplana Guerrero, J. M., and Ylianttila, L.: Intercomparison of erythemal broadband radiometers calibrated by seven UV calibration facilities in Europe and the USA, Atmos. Chem. Phys., 8, 4865-4875, doi:10.5194/acp-8-4865-2008, 2008.