The shadow ring correction in the case of a pyranometer with a thermopile produced by electroplating
Abstract
For the part of the sky that is shadowed by the shadow ring of the pyranometer with electroplated thermopile theoretical values for overcast and cloudless sky, which are to be considered as correction factors for the sky radiation, were calculated for the course of the year. For overcast and cloudless sky experimentally determined values are in good accordance with the theoretical values. A correction factor diagram for the course of the year is given. Furthermore the influence of the circumsolar radiation is discussed. At the time being the circumsolar radiation if measured by the actinometer is contained in the 'direct solar radiation'. Strictly speaking the circumsolar radiation belongs to the sky radiation. In case it is added as correction to the sky radiation only the solar radiation from the sun disk may be considered as 'direct solar radiation'. The correction values regarding the circumsolar radiation are essentially higher than the shadow ring correction if an isotropic sky radiation is assumed.
- Publication:
-
Zeitschrift fur Meteorologie
- Pub Date:
- 1976
- Bibcode:
- 1976ZMete..26...48S
- Keywords:
-
- Meteorological Instruments;
- Pyranometers;
- Sky Radiation;
- Thermopiles;
- Angular Distribution;
- Cloud Cover;
- Electroplating;
- Instrument Errors;
- Mathematical Models;
- Shadows;
- Solar Radiation;
- Instrumentation and Photography