It is important to ensure that the temperatures of the black body furnace and the sample surface are the same. Then, the optical path is switched to the sample heating furnace, and after the sample surface is heated to the set temperature, the radiant energy emitted by the surface is measured. After the temperature of the black body furnace stabilizes at the set temperature, the radiant energy is measured as the background level. Setting the temperatures of the black body furnace and sample heating furnace to the temperature required for measurement. The first step of the measurement procedure consists of This is because the temperature is not even over the surface of such samples, making it impossible for the surface temperature to be measured accurately. Accurate measurement is not possible for curved or powdered samples. Regarding sample form, measurement is usually possible only for plate-like samples. 1 cm in diameter, note that the measurement results may be affected by a small positional displacement if the sample diameter is only around 1 cm.ДЄlso, because it is difficult to use large samples with sample heating furnaces designed for temperatures exceeding 1,000 вЊ, logistical coordination may be required to determine the specifications suitable for the samples. As the spot size required for measurement is approx. Samples with diameters of up to a few centimeters can be set.

There are furnaces that keep the sample in a vertical position but usually the sample mounting is horizontal, as shown in Fig.

m 2),ДЄ sample heating furnace is a device used to heat samples.

Here, C 1: First radiation constant, C 2: Second radiation constantД¬ 1 = 2ПЂhc 2 = 3.741771 Г— 10 -16 (W The emissivity of samples is measured using the black body furnace as a reference. In actual measurement, a black body furnace is used as a body whose properties approach those of an ideal black body. (The vertical axis represents logarithmic values.) 1 shows the spectral radiant emittance of a black body at temperatures of 100, 200, 400, and 600 вЊ calculated with Planck's law. 'Emissivity' is defined by Japanese industrial standard JIS Z 8117 1) as 'the ratio of the radiant emittance of a body to the radiant emittance of a black body at the same temperature as that body.' 'Spectral emissivity' is defined as 'the result of expressing the emissivity as a function of the component wavelengths (wavenumbers or frequencies).' 1)ДЄ black body is 'an idealized object that perfectly absorbs radiation at every wavelength.' 1) The fact that the energy radiated from a black body can be expressed as a function of the wavelength and the temperature of the body is known as 'Planck's law.' Fig. Here, I present a measurement system and some measurement examples related to spectral emissivity spectra, which provide basic data that can be used to evaluate far-infrared radiation materials.

There are increasing expectations that the efficient use of such materials will contribute to energy conservation. Far-infrared radiation materials are used as heaters and refractory materials in industrial products and household electrical appliances, heating and insulating equipment in particular. At the same time, from the viewpoint of energy conservation, it is also important to review our lifestyles and eliminate unnecessary energy consumption. A representative example of this is the introduction of natural forms of energy (e.g., wind power, hydraulic power, and sunlight) as substitutes for fossil fuels, which are a major cause of CO 2 emissions. As the issue of global warming becomes increasingly serious, various measures aimed at reducing CO 2 emissions are being implemented on a global scale.

Radiant energy examples