Michaelson actinograph
From Glossary of Meteorology
Michelson actinometer[edit | edit source]
The radiation is measured in terms of the angular deflection of a blackened bimetallic strip that is exposed to the direct solar beams. In its original form the instrument was also responsive to ambient temperature variations. However, modifications have been introduced that eliminate this source of error.
This actinometer was designed by W. A. Michelson (Met.Zeitschr, 1908)