Monte Carlo uncertainty simulation of surface emissivity at ambient temperature obtained by dual spectral infrared radiometry

Analysis of multi-band pyrometry for emissivity and temperature measurements of gray surfaces at ambient temperature

“…The same principles applied by Araújo et al [26] and Araújo and Martins [27] were used in the selection of the spectral characteristics of the IR detectors: the spectral bands of the detectors are within the spectral range where most radiation is emitted by the target surface, and all spectral bands receive an identical amount of radiation from the target surface, so as to guarantee identical signal-to-noise ratios [28]. Moreover, a unique target temperature T s ¼ 300 K was considered, since this is a typical ambient temperature.…”

“…Table 1 also shows the radiation power fraction of each band (x b ) relatively to the radiation power emitted by a blackbody at 300 K between 2 and 60 lm. Only spectral bands of equivalent power (providing equivalent signal-to-noise ratios) were considered, since published results for dual-band pyrometry indicated that there is no advantage in using wider spectral bands [26,27].…”

“…Only pyrometers uncertainty DT ¼ 0:25 K was considered, as this is a typical value encountered in commercial pyrometers, and the resultant temperature and emissivity uncertainties were reported to be directly proportional to uncertainty DT [26,27].…”

“…Besides, many models ignore the effect of reflected background radiation [4,[10][11][12][13][14][15], which is only valid if the background is much colder than the target surface [16,17]. As a result, more advanced dual-band and multi-band pyrometry systems have been proposed [17][18][19][20][21][22][23][24][25][26][27]. The multi-band model reported by Fu et al [18] indicates that multi-band pyrometry systems may be preferred over multiwavelength systems in the determination of surface temperature.…”

“…Araújo et al [26] investigated and quantified how the emissivity output from dual-band pyrometry systems are affected by the spectral characteristics of the detectors and background temperature, concluding that emissivity uncertainty was minimized for narrow spectral bands, far apart from each other, located towards lower wavelengths, and when the difference between background and target temperatures increased. Araújo and Martins [27] undertook an identical investigation for the temperature output from dual-band systems and reported similar conclusions regarding the variation of temperature uncertainty.…”