K. Leszczynski et al., CALIBRATION OF THE BROAD-BAND RADIOMETERS OF THE FINNISH SOLAR ULTRAVIOLET MONITORING NETWORK, Metrologia, 32(6), 1996, pp. 701-704
The present solar ultraviolet (UV) monitoring network of the Finnish M
eteorological Institute consists of seven sites equipped with erythema
lly-weighted broadband radiometers. Two of the sites are also equipped
with a Brewer spectroradiometer. The Finnish Centre for Radiation and
Nuclear Safety is responsible for testing and calibration of the broa
dband radiometers. An Optronic 742 spectroradiometer is used as a refe
rence instrument, and the broadband radiometers are calibrated against
the Optronic 742 in solar radiation. The Optronic 742 is calibrated a
gainst 1000 W FEL lamps traceable to the NIST. The errors caused by no
nideal radiometric characteristics of the Optronic 742 are numerically
corrected. The uncertainty (2 sigma) of solar UV measurements with th
e Optronic 742 is estimated to be +/- 8 % at 310 nm and the uncertaint
y of the spectroradiometric solar calibration of the Solar Light Model
501 radiometers is estimated to be +/- 11%.