Intercomparison of radiometric irradiance scales in the 90-250-nm wavelength range

The work described in this paper covers an intercomparison of absolute irradiance calibration methods applied at the U.S. National Bureau of Standards (NBS), the SRC Appleton Laboratory, Astrophysics Research Division (ARD), the Max-Planck-Institut fuer Extraterrestrische Physik (MPE), and the Physikalisch- Technische Bundesanstalt (PTB). This was done by determining the MPE and PTB quantum efficiencies of two different calibrated transfer standards developed by the NBS and ARD. The comparison shows that the calibrations agreed within the estimated bounds of uncertainty and also suggests that the uncertainty in the measured electron temperature required in the argon arc source technique may be less than was estimated.