Pyrometer

Emissivity measuring apparatus for measuring an emissivity of a target to be measured, said emissivity measuring apparatus comprising:

• (a) light emitting means for emitting reference light having at least three wavelengths to said target to be measured;
• (b) first light measuring means for measuring the intensity of the reference light emitted by said light emitting means with respect to said at least three wavelengths to produce first signals;
• (c) second light measuring means for measuring the intensity of light reflected by said target with respect to said at least three wavelengths to produce second signals;
• (d) third light measuring means for measuring the intensity of light transmitted through said target with respect to said at least three wavelengths to produce third signals;
• (e) fourth light measuring means for measuring the intensity of light radiated by said target with respect to said at least three wavelengths to produce fourth signals;
• and,
• (f) calculating means for calculating an emissivity .epsilon. (.lambda.) of said target on the basis of a reference light measured value, a reflected light measured value, a transmitted light measured value and a radiated light measured value according to the first, second, third and the fourth signals respectively with respect to each of said at least three wavelengths.