Thermophysical Properties Research Laboratory, Inc.
Phone : 765-463-1581
The emissivity of a material is the relative ability of its surface to emit energy by radiation.
It is the ratio of energy radiated by a particular material to energy radiated by a black body at
the same temperature. A true black body would have an emissivity of 1 while any real object would
have an emissivity less than 1. Emissivity is a dimensionless quantity.