Solar radiation measuring instruments - Terrestrial and extra-terrestrial

A classificatory review is made of solar radiometric instrumentation. Solar pyrheliometers (actinometers), pyranometers, and spectroradiometers are classified and discussed. The 'extraterrestrial' category includes instruments measuring with direct beam only (total and spectral). The 'terrestrial' instruments handle total and spectral measurements with direct beam, global, or diffuse (sky) measurements. Current and historical references are included in the bibliography. Thermoelectric, temperature-compensated, electrically compensated, silver-dish, bimetallic, iron-clad, and uncompensated types of pyrheliometers are reviewed, in addition to thermopile, star, thermoelectric, and bimetallic pyranometers. Some examples of terrestrial and extraterrestrial measurements of solar radiation are included.