The UVB-1 radiometer has a spectral range between 280 and 400 nm but is designed to have a spectral sensitivity close to the erythemal action spectrum. The UVB-1 is designed to be stable over long periods of time and to operate continuously and autonomously in the field. Measurements were taken and stored with the same procedure used in the above cases. The Optronic 754 is equipped with a double monochromator, with a spectral range that extends from 250 nm to 800 nm, with a FWHM of 1.6 nm allowing measurements to be made with a minimum wavelength step of 0.05 nm. The detector is a solid-state photomultiplier, temperature stabilised by the Peltier effect.