What is Spectroscopy by PASCO
Spectroscopy is the investigation and measurement of spectra produced by matter interacting with or emitting electromagnetic radiation. Spectroscopy is defined as any measurement of a quantity as a function of wavelength or frequency now.
What is Spectroscopy used for by PASCO
Spectroscopy is used in physical and analytical chemistry to detect, determine, or quantify the molecular and/or structural composition of a sample. Each type of molecule and atom will reflect, absorb, or emit electromagnetic radiation in its own characteristic way. Spectroscopy uses these characteristics to deduce and analyze the composition of a sample.
Spectrometer Components by PASCO
Types of Spectrometers & Spectroscopy by PASCO
Spectroscopy is the investigation and measurement of spectra produced by matter interacting with or emitting electromagnetic radiation. Spectroscopy is defined as any measurement of a quantity as a function of wavelength or frequency now.
What is Spectroscopy used for by PASCO
Spectroscopy is used in physical and analytical chemistry to detect, determine, or quantify the molecular and/or structural composition of a sample. Each type of molecule and atom will reflect, absorb, or emit electromagnetic radiation in its own characteristic way. Spectroscopy uses these characteristics to deduce and analyze the composition of a sample.
Spectrometer Components by PASCO
- Light sources
- Non-dispersive elements
- Dispersive elements - Prisms
- Dispersive elements - Diffraction Gratings
- Fiver Optic Cables & Spectrometry
- Spectral Resolution
Types of Spectrometers & Spectroscopy by PASCO
- Monochromator - captures one measurement in the UV-VIS spectrum at a particular, predetermined, wavelength or bandwidth.
- Radiometer/light meter - used to measure light in the UVA/VIS, UVA, and VIS spectra.
- Spectrograph - an instrument that separates light by its wavelength or frequency and records the resulting spectral range in a multichannel detector, such as a photographic plate.
- Spectroradiometer - record the radiation spectrum of a light source and calculate parameters such as luminance and chromaticity.
- Spectroscope - a hand-held device used to identify the spectral composition of light.
- Spectrophotometers - Spectrophotometry measures how much light is absorbed by, reflected off, or transmitted through a chemical substance by measuring the intensity of light as the beam passes through a sample.
- Mass Spectroscopy - used by biologists and chemists to measure the mass-to-charge ratio (m/z) of one or more molecules present within a sample.
- NIR & FT-NIR Spectroscopy - Near-infrared spectroscopy uses a halogen light source to produce near-infrared wavelengths (12,000 - 4,000 1/cm) that are composed of overtone and combination bands. Fourier transform near-infrared (FT-NIR) spectroscopy uses a prism or moving grating to separate the individual frequencies emitted from the near-infrared source.
- Optical Spectroscopy - the study of how matter interacts with electromagnetic radiation.
- Raman Spectrometry - a chemical analysis technique that provides detailed information about a sample’s phase and polymorphy, crystallinity and molecular interactions, and chemical structure. In chemistry, raman spectroscopy is used to determine the vibrational modes of molecules.
Diffraction Gratings Ruled and Holographic by HORIBA
Diffraction gratings are manufactured either classically with the use of a ruling engine by burnishing grooves with a diamond stylus, or holographically with the use of interference fringes generated at the intersection of two laser beams.
Classically ruled gratings may be planar or concave and possess grooves, each parallel with the next. Holographic grating grooves may be either parallel or of unequal distribution in order to optimize system performance. Holographic gratings are generated on planar, spherical, toroidal, and many other surfaces.
Regardless of the shape of the surface or whether classically ruled or holographic, the text that follows is applicable to each; explanations are provided where there are differences.
Monochromatic light has infinitely narrow spectral width. Good sources which approximate such light include single mode lasers and very low pressure, cooled spectral calibration lamps. These are also variously known as “line” or “discrete line” sources.
A continuous spectrum has finite spectral width, e.g. “white light.” In principle, all wavelengths are present, but in practice a “continuum” is almost always a segment of a spectrum. Sometimes a continuous spectral segment may be only a few parts of a nanometer wide and resemble a line spectrum.
Basic Equations
Diffraction gratings are manufactured either classically with the use of a ruling engine by burnishing grooves with a diamond stylus, or holographically with the use of interference fringes generated at the intersection of two laser beams.
Classically ruled gratings may be planar or concave and possess grooves, each parallel with the next. Holographic grating grooves may be either parallel or of unequal distribution in order to optimize system performance. Holographic gratings are generated on planar, spherical, toroidal, and many other surfaces.
Regardless of the shape of the surface or whether classically ruled or holographic, the text that follows is applicable to each; explanations are provided where there are differences.
Monochromatic light has infinitely narrow spectral width. Good sources which approximate such light include single mode lasers and very low pressure, cooled spectral calibration lamps. These are also variously known as “line” or “discrete line” sources.
A continuous spectrum has finite spectral width, e.g. “white light.” In principle, all wavelengths are present, but in practice a “continuum” is almost always a segment of a spectrum. Sometimes a continuous spectral segment may be only a few parts of a nanometer wide and resemble a line spectrum.
Basic Equations
- sinα + sinβ = 10-6 knλ
- DV = β-α