Apparatus for calibrating net radiometers in the long wavelength region

Net radiometers measure the net flux of both solar and terrestrial radiation, and should be calibrated separately in each of these wavelength regions. The basic principle of the absolute calibration of radiometers for terrestrial or long-wave radiation is very simple, but the problem of providing adjacent areas with controlled and calculable radiation fluxes is rather complex. The design of a conical radiating cavity has been developed in detail.Les radiom\ue8tres de flux net measurent les diff\ue9rences des flux \ue9nerg\ue9tiques \ue9mis par le soleil et par le sol. Ils devralent \ueatre \ue9talonn\ue9s s\ue9par\ue9ment dans la r\ue9gion pertinente du spectre. Le principe fondamental de l'\ue9talonnage des radiom\ue8tres pour le rayonnement infrarouge absolu du sol est tr\ue8s simple, mais l'irradiation des aires adjacentes par un flux r\ue9glable et calculable constitue un probl\ue8me complexe. L'auteur explique en d\ue9tail l'\ue9laboration d'un corps conique rayonnant.Peer reviewed: NoNRC publication: Ye