An active cavity radiometer is an electrically self-calibrating cavity pyrheliometer that can measure total and spectral solar irradiance.1
References
References
- Willson, Richard C. (November 1981). "Solar total irradiance observations by Active Cavity Radiometers". Solar Physics. 74 (1): 217–229. Bibcode:1981SoPh...74..217W. doi:10.1007/BF00151292. ISSN 0038-0938. S2CID 189827055.