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CaracterizaciĆ³n de radiĆ³metros absolutos de cavidad como patrones primarios de irradiancia solar
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Abstract(s)
RESUMEN: Los radiĆ³metros absolutos de cavidad (ACR) son los instrumentos de mayor nivel metrolĆ³gico para la medida de la irradiancia solar directa (DNI), que trabajan segĆŗn el principio de sustituciĆ³n elĆ©ctrica. Para asegurar su trazabilidad, se comparan (cada 5 aƱos) contra el grupo de patrones WSG que materializan la referencia radiomĆ©trica mundial WRR en el PMOD/WRC (Davos, Suiza). Sin embargo, tambiĆ©n pueden caracterizarse de forma absoluta mediante la calibraciĆ³n, el modelado y cĆ”lculo numĆ©rico de todos sus componentes, en base a una ecuaciĆ³n o funciĆ³n de medida, para obtener su incertidumbre total de medida. Este artĆculo describe distintas tareas realizadas en la caracterizaciĆ³n de dos ACR y los resultados preliminares encontrados. En el caso del Eppley AHF, se han calibrado las magnitudes elĆ©ctricas y el Ć”rea de la apertura de precisiĆ³n, se han determinado la absortancia y el factor de no-equivalencia, asĆ como la dependencia de la corriente en el circuito calefactor de la cavidad con la temperatura. Con estos resultados se esperan alcanzar los objetivos de una incertidumbre inferior a 1000 ppm en DNI y la trazabilidad directa al SI.
ABSTRACT: Absolute Cavity Radiometers (ACR) are the instruments, working under the principle of electrical substitution, of the highest metrological level for measuring Direct Normal Irradiance (DNI). To ensure their traceability, they are compared every 5 years in PMOD/WRC (Davos, Switzerland) to the group of standards WSG realizing the World Radiometeric Reference WRR. However, they can also be characterized in an absolute way through the calibration, modelling and numeric simulation of all their components, based on a measurement function, and obtaining their total measurement uncertainty. This paper describes different labors carried out in the characterization of two ACRs and the preliminary results obtained. In the case of the Eppley Labsā AHF radiometer, the electrical magnitudes and the precision aperture area have been calibrated, effective absorptance and non-equivalence factor have been determined, as well as the dependence on temperature of the electrical current in the heater of the ACR cavity. With these results, the objectives of an uncertainty below 1000 ppm in DNI and the direct traceability to SI can be achieved.
ABSTRACT: Absolute Cavity Radiometers (ACR) are the instruments, working under the principle of electrical substitution, of the highest metrological level for measuring Direct Normal Irradiance (DNI). To ensure their traceability, they are compared every 5 years in PMOD/WRC (Davos, Switzerland) to the group of standards WSG realizing the World Radiometeric Reference WRR. However, they can also be characterized in an absolute way through the calibration, modelling and numeric simulation of all their components, based on a measurement function, and obtaining their total measurement uncertainty. This paper describes different labors carried out in the characterization of two ACRs and the preliminary results obtained. In the case of the Eppley Labsā AHF radiometer, the electrical magnitudes and the precision aperture area have been calibrated, effective absorptance and non-equivalence factor have been determined, as well as the dependence on temperature of the electrical current in the heater of the ACR cavity. With these results, the objectives of an uncertainty below 1000 ppm in DNI and the direct traceability to SI can be achieved.
Description
CIES2020 - XVII Congresso IbƩrico e XIII Congresso Ibero-americano de Energia Solar
Keywords
Solar radiation Radiometry Metrology Calibration Traceability
Citation
Balenzategui, J.L... [et.al.] - CaracterizaciĆ³n de radiĆ³metros absolutos de cavidad como patrones primarios de irradiancia solar. In: CIES2020: As Energias RenovĆ”veis na TransiĆ§Ć£o EnergĆ©tica: Livro de ComunicaƧƵes do XVII Congresso IbĆ©rico e XIII Congresso Ibero-americano de Energia Solar. Helder GonƧalves, Manuel Romero (Ed.). Lisboa, Portugal: LNEG, 3-5 Novembro, 2020, p. 935-942
Publisher
LNEG - LaboratĆ³rio Nacional de Energia e Geologia