solar_lecture_4 - Solar Utilization...

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1 Solar Utilization Solar Radiation Instrumentation Radiant energy fluxes that are of importance to solar  thermal processes include: Beam solar radiation (shortwave) Diffuse solar radiation (shortwave) Reflected solar radiation (shortwave) Long wave radiation that comes from the sky, is reflected  from the surface and reradiates from the surface
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2 Solar Utilization
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3 Solar Utilization
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4 Solar Utilization Solar Radiation Instrumentation There are two major types of instrumentation for  measuring solar radiation: 1. pyrheliometers: uses a collimated detector for  measuring solar radiation from the sun and from a  small portion of the sky around the sun ( beam  radiation ) at normal incidence. Also called an  actinometer. 2. Pyranometer: an instrument for measuring total  hemispherical solar ( beam and diffuse ) radiation,  usually on a horizontal surface. Also called a  solarimeter.
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5 Solar Utilization Research grade pyrheliometers Pyrheliometer: (1) protection cap, (2) window with heater, (3) sight, (5) sensor, (7) humidity indicator, (10) cable for heater Pyrheliometer measurement specifications are subject to International Organization for Standardization (ISO) and World Meteorological Organization (WMO) standards.
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6 Solar Utilization (1) sensor, (2, 3) glass domes, (5) cable, standard length 5 m, (9) desiccant a solar radiation sensor that can be applied in scientific grade solar radiation observations. It complies with the "first class" specifications within the latest ISO and WMO standards. The scientific name of this instrument is pyranometer .
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7 Solar Utilization Solar Radiation Instrumentation The pyranometer can be adapted with a shade ring or disk  to measure diffuse radiation: a shaded pyranometer. The standard and secondary solar radiation instruments  are all pyrheliometers. There has been quite a history for these instruments: Abbot in 1905: a cylindrical black cavity radiation admitted  through a collimating tube. Water flow around and over  the cavity was measured and the temperature  difference measured to determine absorbed energy  flux.
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8 Solar Utilization Solar Radiation Instrumentation Abbot 1932: modified the instrument with two thermally  identical chambers dividing the cooling water between  them. One chamber was heated electrically until its  temperature matched the chamber heated by solar  radiation.  The electrical input was measured and used  to indicate the solar radiation absorbed. Since primary instruments are difficult to use and very 
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This note was uploaded on 10/22/2011 for the course EML 4930 taught by Professor Staff during the Fall '08 term at University of Florida.

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solar_lecture_4 - Solar Utilization...

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