Articles | Volume 8, issue 16
Atmos. Chem. Phys., 8, 4865–4875, 2008

Special issue: One century of solar ultraviolet research

Atmos. Chem. Phys., 8, 4865–4875, 2008

  21 Aug 2008

21 Aug 2008

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 G. Hülsen et al.
  • 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 calibration.

Final-revised paper