Ten of the Yankee UVB-1 Broadband Pyranometers that are deployed in the USDA UV-B Monitoring Program were characterized by the National Institute of Standards and Technology (NIST) for their spectral response, cosine response and linearity prior to their field installation. Since the original characterizations, the instruments have been re-evaluated by Yankee Environmental Systems to determine their stability. Documentation of this stability (or instability) can be demonstrated by viewing the below plots.
Figures 3 and 4 display the original cosine and spectral responses of the network's original broadband meters. Variability in the plots reflects the between instrument variance of the measurements.
