Abstract
IN this quarto pamphlet of seventeen pages (with a plate) the author claims to give a simple method for determining the absolute measure of radiant heat, and describes a self-registering apparatus which gives the intensity of solar radiation at any instant, as also the total heat received by the absorbing surface in a given time. Two circular copper disks are alternately exposed to the source of heat and screened from it, and a thermo-electric couple and galvanometer give the differences of their temperature. The method consists in finding accurately the average time for the temperature-difference of the two plates to be a given (small) amount, positive and negative in turns. By the aid of Newton's law of cooling, which is applicable in this case, the author proves that the intensity of the radiation is proportional to the temperature-difference directly, and the time inversely, and that it is quite independent of the constant of cooling. To verify the last conclusion, the author measured with an instrument of this kind the radiation of a constant source of heat under varying conditions of cooling, and he found that the influence of cooling was completely eliminated.
Sur une nouvelle Méthode de faire des Mesures absolues de la Chaleur rayonnante.
Par Knut Angström. (Upsal: Berling, 1886.)
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C., T. Sur une nouvelle Méthode de faire des Mesures absolues de la Chaleur rayonnante . Nature 35, 580 (1887). https://doi.org/10.1038/035580a0
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DOI: https://doi.org/10.1038/035580a0