5.4. Radiation sensors
Ambient radiation acting on honey bees is sunlight in the visible and near infrared range (ca. 300-3000 nm wavelength, with the maximum in the visible range) and heat radiation in the middle to far infrared range (ca. 3-20 µm wavelength, with the maximum at about 8.5-11 µm at biologically relevant temperatures). The global radiation is the radiation from the upper hemisphere to a horizontal surface. It is the sum of the direct solar and the diffuse sky radiation (in W m-2). Global radiation sensors measure in the solar spectrum from 0.3 to 3 μm wavelength.