Witte H H
Appl Opt. 1972 Apr 1;11(4):777-9. doi: 10.1364/AO.11.000777.
For producing low-loss glass fibers it is essential to know the absorption losses of the bulk material from which the fibers are to be drawn. It has been proposed to determine the absorbed radiation power L(a) from the rise in temperature DeltaT(R) at the surface of the bulk material. The relation between the absorption coefficient alpha and DeltaT(R) is strictly derived and is used to calculate the dimensions that the sample and the wires of the thermocouple must have to make the T(4)-radiation of the sample and from the wires negligibly small. It is essential to eliminate radiation because the emissivities of the wires and of the sample are liable to change considerably with time. In conclusion it is shown that the proposed method is superior by a few orders of magnitude over the conventional methods which are based on measuring the difference between the powers at the input and output of the sample.
为了生产低损耗玻璃纤维，了解用于拉丝的块状材料的吸收损耗至关重要。有人提议根据块状材料表面温度的升高ΔT(R)来确定吸收的辐射功率L(a)。严格推导了吸收系数α与ΔT(R)之间的关系，并用于计算样品和热电偶导线必须具备的尺寸，以使样品和导线的T(4)辐射小到可以忽略不计。消除辐射至关重要，因为导线和样品的发射率可能会随时间发生很大变化。最后表明，所提出的方法比基于测量样品输入和输出功率之差的传统方法优越几个数量级。
