Sensitivity of Spectroradiometric Calibrations in the Near Infrared to Variations in Atmospheric Water Vapor: Preprint

Conference · Mon Mar 01 00:00:00 EST 2004

OSTI ID:15007168

Myers, D R; Andreas, A A

Spectra of natural sunlight and artificial sources are important in photovoltaic research. Calibration of the spectroradiometers used for these measurements is derived from the response to spectral irradiance standards from the National Institute of Standards and Technology (NIST). Some photovoltaic devices respond in the near infrared, or NIR, so spectral measurements and calibrations are needed in this region. Over the course of several calibrations, we identified variations> 5% in spectroradiometer NIR calibration data for a certain spectroradiometer. A detailed uncertainty analysis did not reflect the observed variation. Reviewing calibration procedures and historical data, we noted that the variations were seen in water vapor absorption bands. We used spectral transmission models to compute changes in atmospheric transmission (as a function of water vapor content) over path lengths occurring during calibration. The results indicate that the observed variations result from varying water vapor content. A correction algorithm for adjusting measured data was developed based on our analysis.

• Research Organization: National Renewable Energy Lab., Golden, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99-GO10337
• OSTI ID: 15007168
• Report Number(s): NREL/CP-560-36037; TRN: US200414%%344
• Resource Relation: Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 Mar 2004; Related Information: Prepared for the American Solar Energy Society Annual Conference, 11-14 July 2004, Portland, Oregon
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
47 OTHER INSTRUMENTATION
ABSORPTION
ALGORITHMS
CALIBRATION
SENSITIVITY
SPECTRA
WATER VAPOR
SOLAR ENERGY
CALIBRATION OF SPECTRORADIOMETERS
SPECTRAL IRRADIANCE STANDARDS
NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
PHOTOVOLTAIC RESEARCH
NEAR INFRARED
VARIATIONS IN WATER VAPOR
SOLAR ENERGY - RADIATION