HTHP Home · Issue Contents · Forthcoming Papers
Three-colour pyrometer for the measurement of liquid metal spectral absorptivity at the heating wavelength
Maelenn Le Mener, Coline Bourgès, Elodie Courtois, Mickael Courtois and Thomas Pierre
This article deals with the development of three-colour pyrometer dedicated to the measurement of the normal spectral absorptivity at the wavelength of the heating laser. The absorptivity is a key parameter when a sample is heated by a laser. Among the three wavelengths (λ1, λ2, and λ3), the central one λ2 corresponds to the one of the laser. The proposed methodology is presented during aerodynamic levitation of liquid metallic samples. First, signals from wavelengths λ1 and λ3 are used to evaluate the sample temperature (assumed homogeneous), then signal from λ2, finally, allows to get the normal spectral absorptivity. Beforehand, a first phase of calibration is necessary with a home-made blackbody placed instead of the levitation nozzle. Then the methodology is tested on of iron, zirconium, and nickel materials, which are currently used in high temperature industrial processes.
Keywords: multispectral pyrometry, liquid metal, absorptivity, high temperatures, thermal characterization, aerodynamic levitation, calibration
DOI: 10.32908/hthp.v54.2057