thermal emissivity การใช้

• Thermal emissivity values probably best reflect the effectiveness of radiant barriers.
• Therefore, it is possible to create visibly dark colored surfaces with low thermal emissivity.
• In response to thermal radiation, surface temperature depends on the thermal emissivity of the material.
• This " naturally " low thermal emissivity is found in some formulations of borosilicate or Pyrex.
• Certain properties such as the iron content may be controlled, changing the thermal emissivity properties of glass.
• Other objects on which frost commonly forms are those with low specific heat or high thermal emissivity, such as blackened metals; hence the accumulation of frost on the heads of rusty nails.
• "' Thermal emittance "'or "'thermal emissivity "'is the ratio of the radiant emittance of heat of a specific object or surface to that of a standard black body.
• The different properties of aerosols ( chemical composition, particle size, particle number concentration, optical absorptivity, thermal emissivity, index of refraction, pattern of light scattering, etc . ) require very different kinds of measurement techniques.
• Typical values for a selective surface might be 0.90 solar absorption and 0.10 thermal emissivity . but can range from 0.8 / 0.3 for paints on metal to 0.96 / 0.05 for commercial surfaces-and thermal emissivities as low as 0.02 have been obtained in laboratories.