Contribution to the metrological study of radiometers. A radiometer test-chamber

A test-chamber especially equipped to study the dynamic behavior of radiometers and to calibrate pyrradiometers is described. Temperature as well as humidity and, to some extent, also ventilation speed inside of the test-chamber can be preset within fixed limits to simulate environmental conditions. Short-wave radiometers response may be controlled against a Xenon illuminator. The characteristics of two kinds of thermal radiators, viz. a cylindrical cavity and a large area cavity array, are discussed. An Eppley spectral precision pyranometer and a pyrradiometer of the shielded type have been tested to bring out the capabilities of the test-chamber.