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Title: Reducing broadband shortwave radiometer calibration-bias caused by longwave irradiance in the reference direct beam

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.
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 2160-0414
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Atmospheric and Climate Sciences
Additional Journal Information:
Journal Volume: 07; Journal Issue: 01; Journal ID: ISSN 2160-0414
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S); USDOE Atmospheric Radiation Measurement (ARM) Program
Country of Publication:
United States
14 SOLAR ENERGY; 47 OTHER INSTRUMENTATION; pyranometer; pyrheliometer; pyrgeometer; calibration; solar; shortwave irradiance; longwave irradiance; absolute cavity pyrheliometer; photovoltaic cells; shortwave
OSTI Identifier: