Spectrometer in the context of "Infra-red (IR) spectroscopy"

An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the irradiance of the light but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light or a closely derived physical quantity, such as the corresponding wavenumber or the photon energy, in units of measurement such as centimeters, reciprocal centimeters, or electron volts, respectively.

A spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Spectrometers may operate over a wide range of non-optical wavelengths, from gamma rays and X-rays into the far infrared. If the instrument is designed to measure the spectrum on an absolute scale rather than a relative one, then it is typically called a spectrophotometer. The majority of spectrophotometers are used in spectral regions near the visible spectrum.

An Amici prism, named for the astronomer Giovanni Battista Amici, is a type of compound dispersive prism used in spectrometers. The Amici prism consists of two triangular prisms in contact, with the first typically being made from a medium-dispersion crown glass, and the second from a higher-dispersion flint glass. Light entering the first prism is refracted at the first air–glass interface, refracted again at the interface between the two prisms, and then exits the second prism at near-normal incidence. The prism angles and materials are chosen such that one wavelength (colour) of light, the centre wavelength, exits the prism parallel to (but offset from) the entrance beam. The prism assembly is thus a direct-vision prism and is commonly used as such in hand-held spectroscopes. Other wavelengths are deflected at angles depending on the glass dispersion of the materials. Looking at a light source through the prism thus shows the optical spectrum of the source.

By 1860, Amici realized that one can join this type of prism back-to-back with a reflected copy of itself, producing a three-prism arrangement known as a double Amici prism. This doubling of the original prism increases the angular dispersion of the assembly and also has the useful property that the centre wavelength is refracted back into the direct line of the entrance beam. The exiting ray of the center wavelength is thus not only undeviated from the incident ray, but also experiences no translation (i.e. transverse displacement or offset) away from the incident ray's path.

In a distribution, full width at half maximum (FWHM) is the difference between the two values of the independent variable at which the dependent variable is equal to half of its maximum value. In other words, it is the width of a spectrum curve measured between those points on the y-axis which are half the maximum amplitude.Half width at half maximum (HWHM) is half of the FWHM if the function is symmetric.The term full duration at half maximum (FDHM) is preferred when the independent variable is time.

FWHM is applied to such phenomena as the duration of pulse waveforms and the spectral width of sources used for optical communications and the resolution of spectrometers.The convention of "width" meaning "half maximum" is also widely used in signal processing to define bandwidth as "width of frequency range where less than half the signal's power is attenuated", i.e., the power is at least half the maximum. In signal processing terms, this is at most −3 dB of attenuation, called half-power point or, more specifically, half-power bandwidth.When half-power point is applied to antenna beam width, it is called half-power beam width.

An infrared detector is a detector that reacts to infrared (IR) radiation. The two main types of detectors are thermal and photonic (photodetectors).

The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena.Bolometers and microbolometers are based on changes in resistance. Thermocouples and thermopiles use the thermoelectric effect. Golay cells follow thermal expansion. In IR spectrometers the pyroelectric detectors are the most widespread.

2001 Mars Odyssey is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectrometers and a thermal imager to detect evidence of past or present water and ice, as well as study the planet's geology and radiation environment. The data Odyssey obtains is intended to help answer the question of whether life once existed on Mars and create a risk-assessment of the radiation that future astronauts on Mars might experience. It also acts as a relay for communications between the Curiosity rover, and previously the Mars Exploration Rovers and Phoenix lander, to Earth. The mission was named as a tribute to Arthur C. Clarke, evoking the name of his and Stanley Kubrick's 1968 film 2001: A Space Odyssey.

Odyssey was launched April 7, 2001, on a Delta II rocket from Cape Canaveral Air Force Station, and reached Mars orbit on October 24, 2001, at 02:30 UTC (October 23, 19:30 PDT, 22:30 EDT). As of March 2025, it is still collecting data, and is estimated to have enough propellant to function until the end of 2025. It currently holds the record for the longest-surviving continually active spacecraft in orbit around a planet other than Earth, ahead of the Pioneer Venus Orbiter (served 14 years) and the Mars Express (serving over 20 years), at 24 years, 1 month and 22 days. As of October 2019 it is in a polar orbit around Mars with a semi-major axis of about 3,800 km or 2,400 miles.

Clinical chemistry (also known as chemical pathology, clinical biochemistry or medical biochemistry) is a division in pathology and medical laboratory sciences focusing on qualitative tests of important compounds, referred to as analytes or markers, in bodily fluids and tissues using analytical techniques and specialized instruments. This interdisciplinary field includes knowledge from medicine, biology, chemistry, biomedical engineering, informatics, and an applied form of biochemistry (not to be confused with medicinal chemistry, which involves basic research for drug development).

The discipline originated in the late 19th century with the use of simple chemical reaction tests for various components of blood and urine. Many decades later, clinical chemists use automated analyzers in many clinical laboratories. These instruments perform experimental techniques ranging from pipetting specimens and specimen labelling to advanced measurement techniques such as spectrometry, chromatography, photometry, potentiometry, etc. These instruments provide different results that help identify uncommon analytes, changes in light and electronic voltage properties of naturally occurring analytes such as enzymes, ions, electrolytes, and their concentrations, all of which are important for diagnosing diseases.

Fourier transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer collects high-resolution spectral data over a wide spectral range. This confers a significant advantage over a dispersive spectrometer, which measures intensity over a narrow range of wavelengths at a time.

The term Fourier transform infrared spectroscopy originates from the fact that a Fourier transform (a mathematical process) is required to convert the raw data into the actual spectrum.