Visible Radiation Characteristics of Incandescent Oxides

Abstract

Energy radiated in the visible part of the spectrum of various oxides and their mixtures when heated to red brightness temperatures between 1400\ifmmode^\circ\else\textdegree\fi{} and 2000\ifmmode^\circ\else\textdegree\fi{}K by means of cathode-ray bombardment, and gas-air and oxy-gas flames was measured by an optical pyrometric method. The oxides investigated were urania, ceria, lanthana, neodymia, erbia, yttria, zirconia, thoria, alumina, beryllia, magnesia, and mixtures of thoria with one percent ceria (the Welsbach mantle mixture), one percent and less of urania, one percent neodymia, and one percent manganese oxide. These were either pressed or fused to insure good surface conditions. In general, linear relations were found between the logarithm of the red-blue intensity ratio and the reciprocal of the brightness temperature, and between the logarithm of the candles emitted per unit surface area and the logarithm of the brightness temperature. Different modes of heating gave different radiation curves for the same oxide. Tables are given of the candles per square centimeter and the relative blue brightness for red brightness temperatures of 1400, 1500, 1600, 1700, 1800, 1900, and 2000\ifmmode^\circ\else\textdegree\fi{}K.