Investigation of the Globe Photometer: A Thesis (Classic Reprint)
Excerpt from Investigation of the Globe Photometer: A Thesis
The globe photometer, or more properly, the Ulbricht integrating sphere is not in itself a photometer. It consists of a'hollow globe or sphere, usually of from 18 to 80 inches in diameter, lined with a white material having as nearly as possible a perfectly diffusing surface. Ulbricht demonstrated in 1900 that if a light source be placed in such a globe, the illumination of a small translucent window flush with the globe lining would be proporttonal to the total light flux emitted by the light source withi~ the globe, provided however that the window were screened from the direct rays by a small opaque screen, and the only rays incident upon the window be those reflected from the entire globe lining. This fact immediately brot this novel integrating device to the attention on photometric engineers, for it is necessary to take but one reading to get the total light flux of the source to be measured, Where it is necessary with other devices to take a large number of readings or to rotate the light source. This is not expedient nor accurate for arc lamp photometry on account of the natural variability of arcs. T'he globe can be used in connection with an ordinary photometer bar or some special photometer. It can be demonstratedfmathematicall the the illumination received by the window is a constant, times the total light flux emittsd by the light source within the globe. This constant.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
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The globe photometer, or more properly, the Ulbricht integrating sphere is not in itself a photometer. It consists of a'hollow globe or sphere, usually of from 18 to 80 inches in diameter, lined with a white material having as nearly as possible a perfectly diffusing surface. Ulbricht demonstrated in 1900 that if a light source be placed in such a globe, the illumination of a small translucent window flush with the globe lining would be proporttonal to the total light flux emitted by the light source withi~ the globe, provided however that the window were screened from the direct rays by a small opaque screen, and the only rays incident upon the window be those reflected from the entire globe lining. This fact immediately brot this novel integrating device to the attention on photometric engineers, for it is necessary to take but one reading to get the total light flux of the source to be measured, Where it is necessary with other devices to take a large number of readings or to rotate the light source. This is not expedient nor accurate for arc lamp photometry on account of the natural variability of arcs. T'he globe can be used in connection with an ordinary photometer bar or some special photometer. It can be demonstratedfmathematicall the the illumination received by the window is a constant, times the total light flux emittsd by the light source within the globe. This constant.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Investigation of the Globe Photometer: A Thesis (Classic Reprint)
Excerpt from Investigation of the Globe Photometer: A Thesis
The globe photometer, or more properly, the Ulbricht integrating sphere is not in itself a photometer. It consists of a'hollow globe or sphere, usually of from 18 to 80 inches in diameter, lined with a white material having as nearly as possible a perfectly diffusing surface. Ulbricht demonstrated in 1900 that if a light source be placed in such a globe, the illumination of a small translucent window flush with the globe lining would be proporttonal to the total light flux emitted by the light source withi~ the globe, provided however that the window were screened from the direct rays by a small opaque screen, and the only rays incident upon the window be those reflected from the entire globe lining. This fact immediately brot this novel integrating device to the attention on photometric engineers, for it is necessary to take but one reading to get the total light flux of the source to be measured, Where it is necessary with other devices to take a large number of readings or to rotate the light source. This is not expedient nor accurate for arc lamp photometry on account of the natural variability of arcs. T'he globe can be used in connection with an ordinary photometer bar or some special photometer. It can be demonstratedfmathematicall the the illumination received by the window is a constant, times the total light flux emittsd by the light source within the globe. This constant.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
The globe photometer, or more properly, the Ulbricht integrating sphere is not in itself a photometer. It consists of a'hollow globe or sphere, usually of from 18 to 80 inches in diameter, lined with a white material having as nearly as possible a perfectly diffusing surface. Ulbricht demonstrated in 1900 that if a light source be placed in such a globe, the illumination of a small translucent window flush with the globe lining would be proporttonal to the total light flux emitted by the light source withi~ the globe, provided however that the window were screened from the direct rays by a small opaque screen, and the only rays incident upon the window be those reflected from the entire globe lining. This fact immediately brot this novel integrating device to the attention on photometric engineers, for it is necessary to take but one reading to get the total light flux of the source to be measured, Where it is necessary with other devices to take a large number of readings or to rotate the light source. This is not expedient nor accurate for arc lamp photometry on account of the natural variability of arcs. T'he globe can be used in connection with an ordinary photometer bar or some special photometer. It can be demonstratedfmathematicall the the illumination received by the window is a constant, times the total light flux emittsd by the light source within the globe. This constant.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
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Investigation of the Globe Photometer: A Thesis (Classic Reprint)
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Investigation of the Globe Photometer: A Thesis (Classic Reprint)
80Hardcover
$25.57
25.57
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Product Details
| ISBN-13: | 9780656108992 |
|---|---|
| Publisher: | 1kg Limited |
| Publication date: | 02/02/2019 |
| Pages: | 80 |
| Product dimensions: | 6.00(w) x 9.00(h) x 0.25(d) |
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