Effective Emissivity [e] (also called emittance, but emittance is a less preferable term because it was formerly used to describe radiant exitance). - The measured emissive value of a particular surface under existing measurement conditions (rather than the generic tabulated value for the surface material) that can be used to correct a specific measuring instrument to provide a correct temperature measurement.

Effusivity, Thermal [e] - A measure of the resistance of a material to temperature change
E = ÖkrCp cal Cm2 °C-1 sec½
where:
K = thermal conductivity
r = bulk density
C­­­­­­­­p = specific heat

Emissivity [e] - The ratio of a target surface’s radiance to that of a blackbody at the same temperature, viewed from the same angle and over the same spectral interval; a generic look-up value for a material. Values range from 0 to 1.0. Alternatively, the ratio of a flat, optically polished, opaque target surface radiance to that of a blackbody at the same temperature, viewed from the same angle and over the same spectral interval. The latter definition characterizes the property of the material. When used this way, emittance is used to characterize the material when it is other than flat, optically polished and opaque.

More Emissivity information.

Emittance [e] - The ratio of a target surface’s radiance to that of a blackbody at the same temperature, viewed from the same angle over the same spectral interval; a generic look-up value for a material. Values range from 0 to 1.0.

EMI/RFI Noise - Disturbances to electrical signals caused by electromagnetic interference (EMI) or radio frequency interference (RFI). In thermography, this may cause noise patterns to appear on the display.

Environmental Rating - A rating given an operating unit (typically an electrical or mechanical enclosure) to indicate the limits of the environmental conditions under which the unit will function reliably and within published performance specifications.

Exitance, Radiant [Also Called Radiosity] - Total infrared energy (radiant flux) leaving a target surface. This is composed of radiated, reflected and transmitted components. Only the radiated component is related to target surface temperature.