High accuracy surface-based measurements at various sites in contrasting climatic regions are essential to verify theoretical treatments of radiative transfer in the atmosphere and climate model computations, and for studying trends in surface radiation. Long-term ground observations of the same high accuracy are also required to assess trends within climatic regions.
lDIRECT SOLAR IRRADIANCE
The CHP 1 pyrheliometer is designed to measure the irradiance which results from the radiant flux from a solid angle of 5 °.
The CHP 1 pyrheliometer is compliant with the “First Class” class specified by the international standards.
The CHP 1 pyrheliometer should have a spectral response in the range 200 nm to 4000 nm (a quartz window).
The CHP 1 pyrheliometer expects maximum uncertainty of 2 % for hourly totals and 1% for daily totals.
The SOLYS 2 two-axis sun tracker is an all-weather positioning platform used to point specialized instruments at the sun’s movement across the sky. It is fully automatic and does not require a computer or software for installation.
The integrated GPS receiver automatically configures location and time data.
The SOLYS 2 have a positioning accuracy of ± 0.1? or better.
lDIFFUSE SOLAR RADIATION
CMP 21 has individually optimized temperature compensation. A standard thermistor sensor is fitted to monitor the housing temperature. Each instrument is supplied with its own temperature and directional (cosine) response data. It is the choice for scientific use and in top level solar radiation monitoring networks such as the Baseline Surface Radiation Network (BSRN) of the World Meteorological Organisation.
lGLOBAL SOLAR RADIATION
CMP 22 has all the features of CMP 21 but uses very high quality quartz domes for a wider spectral range, improved directional response, and reduced thermal offsets. Because of the high optical quality of these domes the directional error is reduced below 0.5% up to 80 ° solar zenith angle. Kipp & Zonen is confident that CMP 22 is the best pyranometer currently available.
lDOWN-WELLING INFRARED RADIATION
CGR 4 is the best pyrgeometer currently available and is the choice for scientific use and in top level solar radiation monitoring networks such as the Baseline Surface Radiation Network (BSRN) of the World Meteorological Organisation. CGR 4 has a specially designed silicon meniscus dome that provides a 180 ° field of view and has a hard-carbon coating on the outside to smooth the spectral response and provide extra surface protection. The detector is compensated for changes in sensitivity due to temperature variations.