Characterization of Pyranometer Thermal Offset and Correction of Historiacal Data

Simple item page
dc.contributor.authorCarnicero Dominguez, Bernardo Antonioen
dc.contributor.committeechairHaeffelin, Martial P.en
dc.contributor.committeememberScott, Elaine P.en
dc.contributor.committeememberMahan, James Roberten
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T20:40:43Zen
dc.date.adate2001-07-05en
dc.date.available2014-03-14T20:40:43Zen
dc.date.issued2001-06-15en
dc.date.rdate2002-07-05en
dc.date.sdate2001-06-28en
dc.description.abstractThe Eppley Precision Pyranometer (PSP) is a radiometer used in networks around the world to measure downwelling and upwelling diffuse and total hemispherical broadband solar irradiances. PSP's present an offset in the signal, called thermal offset, produced by a radiation heat exchange between the glass dome, which defines the spectral throughput and the detector. This offset can reach up to 15\% of the total value of the signal when measuring diffuse irradiance under clear sky conditions. The thermal offset is characterized by monitoring the temperature gradient between the dome and detector using thermistors at key locations. The temperatures are acquired by using thermistors. Relationships between the thermal offset and the temperature gradient are established using nighttime data and subsequently used to estimate the offset during daytime. To correct historical data the thermal offset is related to other variables such as the output of a Precision Infrared Pyrgeometer (PIR) or the fraction of cloud cover in the sky. The use of thermistors is a very reliable method to estimate and correct the thermal offset. The relationships between the offset and the IR output and between the offset and the cloud cover fraction provide good estimates of the thermal offset in historical data sets, reducing it 60% to 100% depending on the instrument and the relationship used.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-06282001-131406en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06282001-131406/en
dc.identifier.urihttp://hdl.handle.net/10919/33785en
dc.publisherVirginia Techen
dc.relation.haspartReferences.pdfen
dc.relation.haspartChapter6.pdfen
dc.relation.haspartChapter5.pdfen
dc.relation.haspartChapter4.pdfen
dc.relation.haspartChapter3.pdfen
dc.relation.haspartChapter1-2.pdfen
dc.relation.haspartAppendix1.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCorrection of dataen
dc.subjectCloud cover fractionen
dc.subjectnet IRen
dc.subjectPyranometeren
dc.subjectThermal offseten
dc.subjectPyrgeometeren
dc.titleCharacterization of Pyranometer Thermal Offset and Correction of Historiacal Dataen
dc.typeThesisen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 5 of 7
Thumbnail Image
Name:
Chapter1-2.pdf
Size:
3.29 MB
Format:
Adobe Portable Document Format
Download
Thumbnail Image
Name:
Chapter3.pdf
Size:
5.74 MB
Format:
Adobe Portable Document Format
Download
Thumbnail Image
Name:
Chapter4.pdf
Size:
11.23 MB
Format:
Adobe Portable Document Format
Download
Thumbnail Image
Name:
Chapter5.pdf
Size:
1.48 MB
Format:
Adobe Portable Document Format
Download
Thumbnail Image
Name:
Chapter6.pdf
Size:
47.03 KB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses