Spectrophotometry

spectrophotometerspectrophotometricspectrophotometersspectrophotometricallyphotometrymicro-spectrophotometryphotometricReflectometerspectrographicspectrophotometrical
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.wikipedia
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Spectroscopy

spectroscopiclaser spectroscopyspectroscopist
It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.
Spectral measurement devices are referred to as spectrometers, spectrophotometers, spectrographs or spectral analyzers.

Time-resolved spectroscopy

Time-resolved fluorescence spectroscopytime-resolvedTime-resolved fluorometry (TRF)
It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.
If the process under study is slow, then the time resolution can be obtained with a continuous (i.e., not pulsed) probe beam and repeated conventional spectrophotometric techniques.

DU spectrophotometer

Beckman DU SpectrophotometerBeckman DU ultraviolet spectrophotometerDU line
The last and most popular model became Model D which is better recognized now as the DU spectrophotometer which contained the instrument case, hydrogen lamp with ultraviolent continuum and a better monochromator.
This model of spectrophotometer enabled scientists to easily examine and identify a given substance based on its absorption spectrum, the pattern of light absorbed at different wavelengths.

Beckman Coulter

Beckman InstrumentsBeckmanBeckman Instrument Company
Invented by Arnold O. Beckman in 1940, the spectrophotometer was created with the aid of his colleagues at his company National Technical Laboratories founded in 1935 which would become Beckman Instrument Company and ultimately Beckman Coulter.
In the 1940s, Beckman changed the name to Arnold O. Beckman, Inc. to sell oxygen analyzers, the Helipot precision potentiometer, and spectrophotometers.

Astronomical spectroscopy

spectrumspectroscopicspectra
In astronomy, the term spectrophotometry refers to the measurement of the spectrum of a celestial object in which the flux scale of the spectrum is calibrated as a function of wavelength, usually by comparison with an observation of a spectrophotometric standard star, and corrected for the absorption of light by the Earth's atmosphere.
The flux scale of a spectrum can be calibrated as a function of wavelength by comparison with an observation of a standard star with corrections for atmospheric absorption of light; this is known as spectrophotometry.

Photometer

luminometerastrophotometerflame-photometers
Spectrophotometry uses photometers, known as spectrophotometers, that can measure a light beam's intensity as a function of its color (wavelength).
The principle of spectrophotometers and filter photometers is that (as far as possible) monochromatic light is allowed to pass through a container (cell) with optically flat windows containing the solution.

Photodetector

photocellAmbient lightAmbient light sensor
Then the photon flux density (watts per metre squared usually) of the transmitted or reflected light is measured with a photodiode, charge coupled device or other light sensor.
A 1-D array of photodetectors, as in a spectrophotometer or a Line scanner, may be used to measure the distribution of light along a line.

Fourier-transform infrared spectroscopy

FTIRFourier transform infraredFourier Transform Infrared Spectrometer
This technique is called Fourier transform infrared spectroscopy.
The first low-cost spectrophotometer capable of recording an infrared spectrum was the Perkin-Elmer Infracord produced in 1957.

Colorimetry

colorimetriccolor measurementchromatics
Visible region 400–700 nm spectrophotometry is used extensively in colorimetry science.
It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space tristimulus values and related quantities.

Monochromator

Czerny-Turneroptical spectrophotometersCzerny Turner
Historically, spectrophotometers use a monochromator containing a diffraction grating to produce the analytical spectrum.
A spectrophotometer built with a high quality double monochromator can produce light of sufficient purity and intensity that the instrument can measure a narrow band of optical attenuation of about one million fold (6 AU, Absorbance Units).

Cuvette

cuvettescuvet
Samples are usually prepared in cuvettes; depending on the region of interest, they may be constructed of glass, plastic (visible spectrum region of interest), or quartz (Far UV spectrum region of interest).
This measurement is done with a spectrophotometer.

Photomultiplier

photomultiplier tubephotomultiplier tubesPMT
If a single detector, such as a photomultiplier tube or photodiode is used, the grating can be scanned stepwise (scanning spectrophotometer) so that the detector can measure the light intensity at each wavelength (which will correspond to each "step").
can be used for transmission-mode; favorable response to a NaI:Tl scintillator flashes makes them widely used in gamma spectroscopy and radiation detection; high-temperature bialkali (Na-K-Sb), can operate up to 175 °C, used in well logging, low dark current at room temperature; multialkali (Na-K-Sb-Cs), (also called S20), wide spectral response from ultraviolet to near-infrared, special cathode processing can extend range to 930 nm, used in broadband spectrophotometers; solar-blind (Cs-Te, Cs-I), sensitive to vacuum-UV and ultraviolet, insensitive to visible light and infrared (Cs-Te has cutoff at 320 nm, Cs-I at 200 nm).

Beer–Lambert law

Beer-Lambert LawBeer's lawanalysis of mixtures
If the compound is more concentrated more light will be absorbed by the sample; within small ranges, the Beer-Lambert law holds and the absorbance between samples vary with concentration linearly.
Beer–Lambert law can be applied to the analysis of a mixture by spectrophotometry, without the need for extensive pre-processing of the sample.

Spectroradiometer

Spectroradiometers, which operate almost like the visible region spectrophotometers, are designed to measure the spectral density of illuminants.
Spectrophotometry

Ultraviolet–visible spectroscopy

λ max ultraviolet-visible spectroscopyλ max
Additionally, some specialized instruments, such as spectrophotometers built onto microscopes or telescopes, are single-beam instruments due to practicality.
Spectrophotometry

Chemistry

chemistchemicalChemical Sciences
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology.

Visible spectrum

visiblevisible lightspectrum
It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.

Infrared

IRnear-infraredinfra-red
It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.

Calibration

calibratedcalibratecalibrating
However, they can also be designed to measure the diffusivity on any of the listed light ranges that usually cover around 200 nm - 2500 nm using different controls and calibrations.

Wavelength

wavelengthsperiodsubwavelength
In astronomy, the term spectrophotometry refers to the measurement of the spectrum of a celestial object in which the flux scale of the spectrum is calibrated as a function of wavelength, usually by comparison with an observation of a spectrophotometric standard star, and corrected for the absorption of light by the Earth's atmosphere. Within these ranges of light, calibrations are needed on the machine using standards that vary in type depending on the wavelength of the photometric determination.

Physics

physicistphysicalphysicists
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology.

Materials science

material sciencematerialsmaterials scientist
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology.

Biochemistry

biochemistbiochemicalphysiological chemistry
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology.

Molecular biology

molecular biologistmolecularmolecular biologists
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology.

Astronomy

astronomicalastronomerastronomers
In astronomy, the term spectrophotometry refers to the measurement of the spectrum of a celestial object in which the flux scale of the spectrum is calibrated as a function of wavelength, usually by comparison with an observation of a spectrophotometric standard star, and corrected for the absorption of light by the Earth's atmosphere.