Reducing broadband shortwave radiometer calibration-bias caused by longwave irradiance in the reference direct beam
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
Shortwave radiometers such as pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to consensus reference, maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, and measures the extended broadband spectrum of the terrestrial direct solar beam irradiance, unlike shortwave radiometers that cover a limited range of the spectrum. The difference between the two spectral ranges may lead to calibration bias that can exceed 1%. This paper describes a method to reduce the calibration bias resulting from using broadband ACRs to calibrate shortwave radiometers, by using an ACR with Schott glass window to measure the reference broadband shortwave irradiance in the terrestrial direct solar beam from 0.3 um to 3 um.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office; USDOE Atmospheric Radiation Measurement (ARM) Program
- Grant/Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1340568
- Report Number(s):
- NREL/JA-3B10-67048
- Journal Information:
- Atmospheric and Climate Sciences, Vol. 7, Issue 1; ISSN 2160-0414
- Publisher:
- Scientific Research Publishing Inc. (SCIRP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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