The emissivity of a material, expressed as a fraction. Emittance values range from 0.05 for brightly polished metals to 0.96 for flat black paint.

The ability of a material to emit radiant energy from its surface. Also called emissivity.

ratio of radiation emitted by a body to the emission of a full radiator (blackbody) at the same temperature (a.k.a. emissivity) [--]   Emissionsgrad

The ratio of the energy emitted by an object to the energy that a ‘perfect’ emitter (blackbody) would emit at the same temperature. Related to absorptance through the assumptions in Kirchoff’s Law. See Conservation of Energy.

The rate at which emission occurs.

The ratio of the radiant flux emitted by an ideal, perfect emitter and absorber of thermal radiation at the same temperature and under the same conditions.

Emittance refers to the ability of the surface to emit radiant energy. Emissivity ranges from 0 to 1 and a lower value indicates a reflective surface with a low level of radiation.

The capability of the surface to emanate radiant energy.

The ratio of the radiant flux emitted by a specimen to that emitted by a blackbody at the same temperature and under the same conditions.

The fractional quantity of available radiative energy emitted by a material.

A measure of the propensity of a material to emit thermal radiation.

(Or emissive power.) Emitted irradiance.

The obsolete term for the radiant flux per unit area emitted by a body, or exitance.