Fachspezifische Schlagworte

• Differential Scanning Calorimetry
• X-Ray Powder Diffraction
• Fourier Transform Infrared Spectroscopy
• Particle Analysis
• Optical Microscopy
• UV-VIS Spectrophotometry
• Photometry
• Microscopy
• Surface Area Analysis
• Zeta-Potential Measurement
• Differential Thermal Analysis
• Thermogravimetric Analysis
• Biogeochemie
• Geochemie
• Mineralogie

Kategorien

• Laboratorien

Instrumentierung

Laboratory instrumentation

Instrumente

• Zeta-Potential Analyzer

• Surface Area Analyzer

• Particle Analyzer

• Optical Microscope

• UV-VIS Spectrophotometer

• Thermal Analysis Platform

• Fourier Transform Infrared Spectrometer

  FTIR Spectrometer - Fourier Transform Infrared Spectrometer

  Traditional (dispersive) infrared techniques experience difficulties due to the '1 wavenumber at a time' nature of data acquisition. This leads to either a poor signal to noise ratio in a spectrum or a very long time needed to obtain a high quality spectrum. Both these situations cause problems with kinetic work. The first gives inherent large errors, the second prohibits in-situ work. These problems can be overcome using Fourier transform infrared spectroscopy (FT-IR) that is based on the interferometer originally designed by Michelson and a mathematical procedure developed by Fourier that converts response from the 'time' to the 'frequency' domain.

  In the Michelson interferometer a parallel, polychromatic beam of radiation from a source (A) is directed to a beam splitter (B), made from an infrared transparent material, such as KBr. The beam splitter reflects approximately half of the light to a mirror, known as the fixed mirror (C), which in turn reflects the light back to the beam splitter. The rest of the light passes through to a mirror, moving continuously, at a known velocity, back and forth along the direction of the incoming light and this is known as the moving mirror (D). Upon reflection from the moving mirror, radiation is then directed back to the beam splitter. At the beam splitter some of the light that has been reflected from the fixed mirror combines with light reflected from the moving mirror and is directed towards the sample. After passing through the sample (E) the radiation is focused onto the detector (F). The detectors are sufficiently fast to cope with time domain signal changes from the modulatio n in the interferometer. Additional information available at http://physics.nist.gov/Divisions/Div842/Gp1/fts_intro.html (Source: Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16.3. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects pision, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords)

• Photometer

  Photometers are instruments used for measuring the luminance, luminous intensity, or luminance of a light source; similar to a radiometer, but with an output weighted by the wavelength response of the human eye. (Source: Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16.3. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects pision, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords)

• X-Ray Powder Diffractometer

  An x-ray powder diffractometer is primarily used for the identification of phases in powder form. An x-ray beam of known wavelength is focused on a powdered sample and x-ray diffraction peaks are measured using a germanium detector; the d-spacing of the observed diffraction peaks is calculated using Bragg's Law [n*lamda = 2dsin(theta)]. The Scintag Pad V automated powder diffractometer uses a Cu x-ray tube with variable filters, a four-sample changer, and a low-noise, high efficiency, liquid-nitrogen cooled germanium detector. The goniometer is automated and software packages are run from a PC running Windows NT 4. A number of Scintag software packages are available for routine powder diffraction data acquisition, background correction and peak identification. Unknowns can be matched to JCPDS cards in an on-line database. Other software is available for quantitative analysis of powder mixtures, unit cell refinement, Rietveld analysis, and GSAS structural analysis. Samples sho uld be prepared as powders with a grain size of 10 um (approximately), and typically about 100 milligrams of sample is required. Additional information available at "http://www.gps.caltech.edu/facilities/analytical/xrd.html" [Summary provided by Caltech] (Source: Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16.3. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects pision, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords)

Beziehungen

• ist Teil von
• Umweltmineralogie und Biogeochemie-Labore
• steht in Zusammenhang mit
• Röntgendiffraktometrie Analyse (RDA)