Results 151 to 160 of about 1,938 (181)

Copper disk pyrheliometer of high accuracy

Applied Optics, 1983
A copper disk pyrheliometer has been designed and constructed that utilizes a new methodology to measure solar radiation. By operating the shutter of the instrument and measuring the heating and cooling rates of the sensor at the very moment when the sensor is at the same temperature, the solar radiation can be accurately determined with these rates ...
C K, Hsieh, X A, Wang
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Two simple and novel pyrheliometers

Solar Energy, 1997
Two simple and novel pyrheliometers have been designed and constructed based on a new methodology to measure solar irradiance. They are respectively the double-sensor and the single-sensor methods. The sensor surface is made of heavily oxidized stainless steel foil, which is formed as a circular disk and thermally joined to a large stainless steel ring
S.X Cheng, H.P Hu, L Chen
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An easily designed and constructed photovoltaic pyrheliometer

Solar & Wind Technology, 1988
Abstract In this paper, a simple Normal Incident Pyrheliometer, called a photovoltaic pyrheliometer, is proposed. The device consist of, as the name implies, a polycrystalline solar cell and a collimator tube. The collimator tube has a square field.
A.M. Mujahid, A.R.M. Alamoud
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A novel pyrheliometer of high accuracy

Solar Energy, 1987
Abstract In this paper, analyses have been carried out for a novel blackbody model, which is made by employing a hemispheric mirror. It is calculated that the effective absorptance of the model can approach unity by correctly choosing the coatings and the geometric parameters.
Z.M. Zhang, X.S. Ge, Y.F. Wang
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Evaluating calibrations of normal incident pyrheliometers

SPIE Proceedings, 2010
When an Eppley Normal Incident Pyrheliometer is calibrated against an Eppley Hickey Frieden Absolute Cavity Radiometer, the instrument systematically deviates from the absolute cavity readings. The reason for this deviation is not understood. Comparisons are made between one pyrheliometer and an absolute cavity radiometer on selected clear days over
Frank Vignola, Fuding Lin
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A transient calorimeter pyrheliometer of high accuracy

Solar Energy, 1990
Abstract The problems of how to improve the accuracy and keep the stability of the transient calorimeter pyrheliometer have been solved by the following methods: (i) a hemispheric mirror shell with a small hole at its top is situated over a copper disk sensor. The inner wall of the shell has high reflectivity, acting as a specular reflector.
S.X. Cheng, X.S. Ge, J.A. Li, H.Q. Feng
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Cloud Reflection Effects in Pyrheliometer Records*

Bulletin of the American Meteorological Society, 1946
“Inordinately” high values of solar radiation, noted at a high altitude desert station, were found to be caused by reflection from lower surfaces of clouds. Descriptions of these reflective phenomena, with explanatory diagrams and illustrative curves, are here presented.
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Accurate solar ‘constant’ determinations by cavity pyrheliometers

Journal of Geophysical Research: Oceans, 1978
Total solar irradiance was observed outside the earth's atmosphere by three types of absolute cavity pyrheliometer in a June 1976 sounding rocket experiment. The 1367 W/m2 average solar ‘constant’ result is uncertain by less than ±0.5%, the most accurate determination to date.
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Test Method for Calibration of Pyrheliometers by Comparison to Reference Pyrheliometers

2008
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pyrheliometer, n.

2023
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