ASTM E2529-06e1由美国材料与试验协会 US-ASTM 发布于 2006。
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4.1 Assessment of the spectrometer resolution and instrument line shape (ILS) function of a Raman spectrometer is important for intercomparability of spectra obtained among widely varying spectrometer systems, if spectra are to be transferred among systems, if various sampling accessories are to be used, or if the spectrometer can be operated at more than one laser excitation wavelength.
4.2 Low-pressure discharge lamps (pen lamps such as mercury, argon, or neon) provide a low-cost means to provide both resolution and wave number calibration for a variety of Raman systems over an extended wavelength range.
4.3 There are several disadvantages in the use of emission lines for this purpose, however.
4.3.1 First, it may be difficult to align the lamps properly with the sample position leading to distortion of the line, especially if the entrance slit of the spectrometer is underfilled or not symmetrically illuminated.
4.3.2 Second, many of the emission sources have highly dense spectra that may complicate both resolution and wave number calibration, especially on low-resolution systems.
4.3.3 Third, a significant contributor to line broadening of Raman spectral features may be the excitation laser line width itself, a component that is not assessed when evaluating the spectrometer resolution with pen lamps.
4.3.4 An alternative would use a Raman active compound in place of the emission source. This compound should be chemically inert, stable, and safe and ideally should provide Raman bands that are evenly distributed from 0 cm-1 (Raman shift) to the C-H stretching region 3000 cm -1 and above. These Raman bands should be of varying bandwidth.
4.4 To date, no such ideal sample has been identified; however carbon tetrachloride (see Practice E1683) and naphthalene (see Guide E1840) have been used previously for both resolution and Raman shift calibration.
4.5 The use of calcite to assess the resolution of a Raman system will be addressed in this guide. Calcite is a naturally occurring mineral that possesses many of the desired optical properties for a Raman resolution standard and is inexpensive, safe, and readily available.
4.6 The spectral bandwidth of dispersive Raman spectrometers is determined primarily by the focal length of the spectrometer, the dispersion of the grating, and the slit width. Field portable systems typically operate with fixed slits and gratings and thus operate with a fixed spectral bandwidth, while in many laboratory systems the slit widths and gratings are variable. The spectral bandwidth of Fourier-Transform (FT)-Raman systems is continuously variable by altering the optical path difference of the interferometer and furthermore is capable of obtaining much lower spectral bandwidth than most practical dispersive systems. Therefore, data obtained of a narrow Raman band on a FT-Raman system can be used to determine the resolution of a dispersive Raman ......
光谱仪 微型光谱仪是便携拉曼的“心脏”,光谱仪的性能直接影响拉曼的光谱分辨率,灵敏度和光谱检测范围。目前国内拉曼采用的光谱仪相较进口产品存在较大差距。例如,国内拉曼的分辨率一般在10cm-1左右,而国外拉曼的分辨率一般在5cm-1左右,其中美国B&WTek多种型号的光谱仪能达到3.5cm-1(ASTM标准方法测量)。另外,国外光谱仪在CCD封装,噪声控制等方面表现更佳。...
新标准规定了用色散型显微激光拉曼光谱仪检测物质拉曼光谱的方法原理、校准用器具及材料、仪器环境、仪器、试样的制备、分析测试,以及安全、维护注意事项,适用于色散法激光拉曼光谱的常规分析。 本标准适用于色散法激光拉曼光谱的常规分析。...
、ASTM E1840和E2529-06标准的全自动化仪器测试 完全符合GMP/cGMP、GLP和CFRp11要求 开放架构版本,具备更高横向分辨率,适用于分析较大的样本(譬如艺术品) 使用的技术受以下专利保护: US 6141095; US 7102746...
光谱仪方面微型光谱仪是便携拉曼的“心脏”,光谱仪的性能直接影响拉曼的光谱分辨率,灵敏度和光谱检测范围。目前国内拉曼采用的光谱仪相较进口产品存在较大差距。例如,国内拉曼的分辨率一般在10cm-1左右,而国外拉曼的分辨率一般在5cm-1左右,其中美国B&WTek多种型号的光谱仪能达到3.5cm-1(ASTM标准方法测量)。另外,国外光谱仪在CCD封装,噪声控制等方面表现更佳。...
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