Fourier transform spectrometer for spectral emissivity measurement in the temperature range between 60 and 1500°C

Apparatus for measuring the emittance of materials from far infrared to visible wavelengths in extreme conditions of temperature

“…In the geosciences field, emittance spectra are also unavoidable data to be able to understand heat transfer and transformation occurring in the earth mantle [3,4]. Several devices [5][6][7][8][9][10][11][12][13][14] have been already published around this subject but most of them are limited to the characterization of the emissivity of opaque materials in restricted spectral ranges. In this paper the technical details of an experimental apparatus designed to measure the emittance spectra of opaque and semi transparent materials in the whole spectral range where thermal emission is produced (i.e.…”

Measurements of the directional spectral emissivity based on a radiation heating source with alternating spectral distributions

“…Many measurement methods have been developed to measure the spectral emissivity of materials at various temperatures and spectral ranges. The direct measurement method of the spectral emissivity was widely used that compare the sample spectral intensity to the blackbody spectral intensity at the same temperature [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. For example, Rozenbaum et al [4] used a spectroscopic method to measure the directional spectral emissivity of semi-transparent materials for wavelengths of 10-12000 cm À1 and temperatures of 600-3000 K with the sample heated by a carbon dioxide laser.…”

“…Hanssen et al [7] used a facility at NIST to measure spectral emissivities for wavelengths of 1-20 lm and temperatures of 600-1400 K. The sample surface temperature was measured using a non-contact method with a sphere reflectometer. Dai et al [9] used a spectral emissivity measurement system with a Fourier transform spectrometer with a spectral range between 0.6 and 25 lm. The sample temperature was controlled between 60 and 1500°C by a thermocouple and pyrometer monitoring.…”

Analysis of the Accuracy of Methods for the Direct Measurement of Emissivity

“…We will assume that the temperature of the radiometer remains constant during the experiment, so R(λ) and S 0 (λ) are considered to be temperature independent. It is interesting to remark that most authors [2][3][4][5][6] multiply the S 0 (λ) term by the response function. Finally, L(λ, T ) in Eq.…”

“…On the other hand, L * s (λ, T ) is determined by the radiometer calibration, which basically involves calculating R(λ) and S 0 (λ) [2][3][4][5][6]. The usual way to perform the calibration is to measure the blackbody signal (S bb ) at two different temperatures, T 1 and T 2 ,…”