On temperature determining by maximum spectral radiation isothermal system of opaque bodies

It is shown that, for the temperature determination of the isothermal opaque bodies system, one can use the same techniques those are used to determine the temperature of a free-radiating opaque body. For an isothermal system of opaque bodies, a relationship was obtained, which relates the wavelength of maximum spectral radiation, the spectral effective emissivity and the thermodynamic temperature. In particular, this relationship can be used as an additional condition to determine the thermodynamic temperature of the isothermal system of bodies by the thermal radiation spectrum of the target surface, when the effective emissivity of the radiation source is unknown. (paper)