An experimental and computational study of the normal spectral emissivity during melting of various metals was carried out, the installation scheme and the method of conducting experiments were given. The possibilities of the electromagnetic theory for describing the dependence of the behavior of the normal spectral emissivity of metals and semimetals are evaluated.

The emissivity of copper, silver and gold has been experimentally determined in the temperature range, including the solid-liquid phase transition. The measurement error ranged from 5 to 8%.

An experimental study of the normal spectral emissivity of technical nickel, palladium and platinum in the solid polished and liquid phases near the melting points was carried out by the radiation method. The emission measurement was recorded by the bandwidth of the applied narrowband filters. The dependence of metal emission on the wavelength in the range of the radiation spectrum 0.26−10.6 µm is obtained. A comparative analysis with the literature data of other authors is carried out. A theoretical calculation of the emission is given according to the classical electromagnetic theory — Hagen 's formula and Rubens.

An experimental study of the normal spectral emission ability of technical titanium grade VT1-00 in the melting region was carried out. The scheme of the upgraded direct vision radiometer with replaceable narrow−band dispersion filters of the spectral range 0.69-10.9 µm is given. The estimation of the possibility of calculating the emission capacity of titanium according to electromagnetic theory is carried out.