2024-07-25 ヒューストン大学(UH)
＜関連情報＞
- https://uh.edu/news-events/stories/2024/july/07252024-bao-thermal-imaging-thermography-.php
- https://www.cell.com/device/fulltext/S2666-9986(24)00342-9
近赤外黒体放射スペクトルを用いた光熱触媒の表面温度測定用非接触温度計 Non-contact thermometer for measuring surface temperature of photothermal catalysts using near-infrared black-body radiation spectrum
Meiraba Chirom,Chengzhen Qin,Feng Lin,…,Xiaonan Shan,Stacey Louie,Jiming Bao
Device Published:July 24, 2024
DOI:https://doi.org/10.1016/j.device.2024.100467
Highlights
- Overcoming limitations of single-wavelength and multi-spectral thermometry
- Simple calibration to eliminate wavelength- and temperature-dependent emissivity
- Accurate temperature determination over a wide temperature range
- Revealed a huge temperature gradient in a catalyst powder under laser heating
The bigger picture
Thermal cameras and infrared (IR) thermometers are widely used due to their sensitivity, speed, and non-contact nature. However, they cannot provide accurate readings because they rely on emissivity—a parameter that varies with temperature—to determine temperature. Multi-spectral techniques address this by measuring IR intensity at multiple wavelengths, but their accuracy depends on their emissivity models. We designed a technique using a near-IR (NIR) spectrometer to measure the continuous spectrum and fit it using the ideal black-body radiation formula. This technique includes a simple calibration step to eliminate temperature- and wavelength-dependent emissivity. We demonstrate this technique by measuring the temperature of a heating stage with errors less than 2°C and measuring the surface temperature gradient of a catalyst powder under laser heating.
Summary
Electrons with energies higher than the thermal distribution, also known as hot electrons, can help reduce activation energy and improve selectivity in photothermal catalysis. To better understand this process, one needs to measure the non-thermal contributions, which requires accurately determining the catalysts’ temperature. We present a non-contact optical technique for measuring the surface temperature of catalysts. This technique utilizes a spectrometer to measure the near-infrared (NIR) emission spectrum (950–1,600 nm). Since the measurement does not rely on black-body emission intensity alone, it does not suffer from temperature-dependent emissivity and other related issues. The NIR thermometer can achieve an accuracy of 1°C at 200°C and above. The use of NIR continuous spectral fitting can help understand non-thermal contributions in photothermal reactions and solve problems in fields where accurate high surface temperature measurement is required.
Graphical abstract
