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Infrared Thermography in Convective Heat Transfer
Published in Wen-Jei Yang, Handbook of Flow Visualization, 2018
Giovanni Maria Carlomagno, Luigi de Luca
In the LW band, the radiometer uses germanium optics with a peak coating at about 10µm; the detector is typically manufactured from mercury cadmium telluride (HgCdTe), which gives a spectral response between 8 and 14 µm wavelengths. Mercury cadmium telluride detectors can be used also in the SW window.
Laser Output Measurement
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Since a typical photon energy is 2 eV ≈ 3 × 10−19 J, e/hv is of the order of 0.5 A/W. Normal detection efficiencies ηD exceed 0.5 at optical wavelengths (500–800 nm), leading to typical responsivities of 0.25 A/W. Silicon photodiodes have a narrow spectral response range (400 nm–1.1 μm). The response peak is at about 800 nm. Germanium photodiodes also have a narrow spectral response range (800 nm–1.8 μm). The response peak is at about 1.5 μm. Photodiodes usually have a power range of 1 nW–50 mW for CW lasers or 1 pJ–1 μJ for pulsed lasers and a short response time of about 100 ms. Photodiodes are best for measuring low power output of CW lasers or low energy output of pulsed lasers. Because their spectral response is wavelength dependent, calibration is always required when measuring the power of lasers with different wavelengths. Manufacturers should attach a calibration data sheet to their laser power meters that use a photodiode as the detector. Several other semiconductor photodetectors with different spectral response ranges are available commercially. For example, the spectral response ranges are from 1.0 to 3.6 μm, 1.0 to 5.5 μm, and 2 to 22 μm for indium arsenide photodetectors, indium antimonide photodetectors, and mercury cadmium telluride photodetectors, respectively.
In-Situ Metrology
Published in Robert Doering, Yoshio Nishi, Handbook of Semiconductor Manufacturing Technology, 2017
Complete spectra from 1.5 to 25 μm wavelength can be obtained in fractions of a second using a FTIR spectrometer. The core of a FTIR is typically a Michelson Interferometer consisting of a beam splitter and two mirrors, one of which moves [30]. As shown in Figure 25.9, incoming radiation in a parallel beam impinges on the beam splitter and is split roughly in half into beams directed at the mirrors. The reflected light recombines at the beamsplitter to form the outgoing radiation. If the mirrors are equidistant from the beam splitter, then the radiation recombines constructively. If the paths differ by one-fourth wavelength, then the beams combine destructively. As the moving mirror travels at constant velocity, the radiation is amplitude modulated, with each frequency being modulated at a unique frequency that is proportional to the velocity and inversely proportional to the wavelength. Thus, radiation with twice the wavelength is modulated at half the frequency. The key requirements for such a FTIR spectrometer are that they are vibration immune, rugged, permanently aligned, and thermally stable. Another key issue for accurate quantitative analysis is detector linearity. Mercury cadmium telluride (MCT) detectors are high sensitivity infrared detectors, but are notoriously nonlinear. Detector correction methods are required to linearize the response. All these requirements have been addressed, making FTIR a commercially available sensor [31] for possible use in SC manufacturing.
Development of Detailed Surface Reaction Mechanism of C2H4/C3H6 Oxidation on Pt/Al2O3 Monolith Catalyst Based on Gas Phase and Surface Species Analyses
Published in Combustion Science and Technology, 2022
Set Naing, I Putu Angga Kristyawan, Hiroshi Murakami, Satoshi Hinokuma, Yuhei Matsumoto, Tomohito Omori, Yanlei Wang, Hideaki Yokohata, Michiharu Kawano, Hiroyuki Takebayashi, Akira Miyoshi, Daisuke Shimokuri
Variations of the adsorbed surface species on the sample catalyst are identified by using in-situ FTIR. The spectral information (peak position, peak value, and their variation with temperature) provide information about the adsorbed species, adsorption regime and qualitative variations of their coverage (Hinokuma et al. 2016; Satsuma and Shimizu 2003). In-situ FTIR spectra of the chemisorbed substrate on each catalyst are acquired by a FT/IR-6600 (Jasco). The samples are prepared by scraping the washcoat of monolith honeycomb catalyst and grinding them. On this measurement, a temperature-controllable diffuse reflectance reaction cell and a mercury cadmium telluride (MCT) detector are used. The cell is heated to 300°C for 30 min, and then, the background spectra at each temperature (50 ~ 300°C) are collected after cooling to the room temperature. Then, the powdered catalyst is then exposed to the test gas stream under various temperature conditions for over 5 min before its spectrum is collected.
Development of Surface Reaction Mechanisms of CO / O2 on Pt and Rh for Three Way Catalyst based on Gas Phase and Surface Species Analyses
Published in Combustion Science and Technology, 2021
Daisuke Shimokuri, Hiroshi Murakami, Satoshi Hinokuma, Yuhei Matsumoto, Set Naing, Koki Naito, Hideaki Yokohata, Hiroyuki Takebayashi, Akira Miyoshi
The absorption regimes as well as qualitative amount of those species are known to be identified with in-situ FTIR technique. In-situ FTIR spectra (peak position, peak value, and their variation with temperature) bring us information about the adsorbed species, adsorption regime, and qualitative variations of their coverage (Hinokuma et al. 2016; Satsuma and Shimizu 2003). In this study, in-situ FTIR spectra were obtained with FT/IR-6600 (Jasco) for powdered catalysts. On the measurement, a temperature-controllable diffuse reflectance reaction cell and a mercury cadmium telluride detector were used. The cell was heated to 500°C for 30 min, and then, the background spectra at each temperature (from room temperature to 500°C) were collected after cooling to the room temperature. Then, each catalyst was exposed for over 5 min to the test gas stream (CO/O2 mixture) and the spectrum was collected under the same conditions as monolith honeycomb experiments. The surface reaction mechanisms were developed based on the results of in-situ FTIR measurement as well as the gaseous conversion experiments.
High-resolution infrared spectrum of CHD279Br: ro-vibrational analysis of the ν5 and ν9 fundamentals
Published in Molecular Physics, 2020
P. Stoppa, D. De Vito, S. Giorgianni, A. Baldacci, R. Wugt Larsen
The high-resolution (0.0035 cm−1) absorption infrared spectrum of CHD279Br was recorded using the Bruker IFS 120 HR FTIR spectrometer at MAX-lab (Lund University, Sweden). The instrument was equipped with a Globar source, a KBr beam splitter and a high sensitivity mercury – cadmium telluride (MCT) detector. The measurements were carried out in the range 700–900 cm−1 at T = 296 K and a sample pressure of about 240 Pa using a 0.5-L White type absorption cell equipped with CsI windows with a total optical path length of 192 cm. The collected interferograms (492 co-added scans) were post-zero-filled and the absorption line positions were fitted using the Microcal Origin Pro 8 software package. The absolute wavenumber scale of the resulting spectrum was calibrated against absorption lines of CO2 [35]. The accuracy of measurements for unblended lines was estimated to be 0.002 cm−1 which is the result of the strong collisional self-broadening as observed for CH3Br [36].