Since March 1982 surface radiation balance measurements have been carried out at Georg-von-Neumayer. The radiation signals were taken at one minute intervals and stored as averages over 10 minutes. They include:
- global radiation (pyranometer CM11, Kipp+Zonen),
- reflected solar radiation (pyranometer CM11, Kipp+Zonen),
- downward long-wave radiation (pyrradiometer Lange),
- upward long-wave radiation (pyrradiometer Lange),
- sunshine duration (Solar 111, Haenni).
In March 1992 the radiation measurements at Neumayer were extended in order to fulfil the standards of the Baseline Surface Radiation Network (BSRN). The pyrradiometers were replaced by pyrgeometers (PIR, Eppley), the averaging period was first reduced to 5 minutes, in 1998 with measurements every 5 seconds to 1 minute and the following quantities are now additionally measured:
- diffuse sky radiation (pyranometer CM11, Kipp+Zonen),
- direct solar radiation (NIP, Eppley mounted on a sun tracker),
- OG1 (global>530nm, pyranometer CM11, Kipp+Zonen),
- RG8 (global>695nm, pyranometer CM11, Kipp+Zonen),
- UV (300-370nm, TUVR, Eppley).
The pyranometers and pyrgeometers are ventilated with slightly preheated air to minimize hoar frost problems and zero offsets during cloudless and windless conditions. The instruments are maintained continuously throughout the year. After one year of operation they get re-calibrated at the Word Radiation Center according the World Radiometric Reference (WRR).
Meanwhile the short-wave fluxes get measured with CMP 22 pyranometers from Kipp+Zonen. For the longwave fluxes we use PIR and CGR4 pyrgeometers from Eppley and Kipp+Zonen. Since March 2009 the sunshine duration is measured using a CSD 3 shunshine duration sensor (Kipp&Zonen).