A spectrometer is an instrument used to separate and measure the wavelengths of light. It is also used to detect the properties of a substance by analyzing its spectrum.

A spectrometer can also be used to detect elements in materials or identify compounds in the environment. A spectrometer uses a diffraction grating, prism, or prism/diffraction grating combination to disperse radiation into its component wavelengths and then measures these wavelengths using a detector such as a photomultiplier tube (PMT) or charge-coupled device (CCD).

There are four main types of spectrometers: absorption, emission, dispersion, and Raman.

An absorption spectrometer is most commonly used for analyzing gases by measuring their absorption of infrared radiation from a flame or other source (photoelectron spectroscopy).

The absorption spectrum gives information on the gas's composition and temperature. Absorption-type spectrometers are often classified according to the type of radiation they measure: optical (e.g., UV/Vis), microwave (e.g., Fourier transform microwave), radio frequency (e.g., electron spin resonance), X-ray (e.g., XRF), etc.

An emission spectrometer is used to measure the emission spectrum of a sample, which can be used to identify the chemical composition of a sample. The amount of light emitted by a sample is proportional to the intensity of the source and inversely proportional to the path length (Beer-Lambert law).

An emission spectrum can be obtained using a diffraction grating or prism to disperse an intense point source or using a monochromator in conjunction with an intense line source (e.g., laser).

Emission-type spectrometers are often classified according to the type of radiation they measure: optical (e.g., UV/Vis), microwave (e.g., Fourier transform microwave), radio frequency (e.g., electron spin resonance), X-ray, etc.

A dispersion spectrometer disperses light from an extended source into its component wavelengths and then measures these wavelengths using a detector such as a photomultiplier tube (PMT) or charge-coupled device (CCD).

A dispersive instrument may also be referred to as a spectral dissection microscope or simply a spectral microscope when used for microscopy applications, but this usage is not universal. Dispersive instruments are typically classified according to their method of dispersing radiation: grating, prism, diffraction grating, etc.

An emission spectrometer is a type of emission-type spectrometer that uses a broad-band source to illuminate the sample. The light emitted by the sample is dispersed by a diffraction grating or prism and then passed through an energy filter (e.g., monochromator) to select photons of specific energy.

This light is then detected using a PMT or CCD detector. The data collected from the detector is then analyzed using software to generate spectral data which can be displayed in either tabular or graphical form.

Ultraviolet light can reach farther and go through things more easily than other types of light. So, it can be used to figure out what compounds are in the air or on things.

UV-VIS is a new method that has only been around for a short time. Scientists and engineers use ultraviolet spectroscopy to find out about the chemical and physical properties of materials.

UV-VIS can find elements in materials, figure out quantities of each component there are, and find problems in materials.

A cuvette is a small container with straight sides and a round or square hole in the middle. Most of the time, one end is sealed, and the other end has a cap.

To get rid of refraction artefacts, standard cuvettes have square or rectangular cross-sections. The 10mm cuvette (path length) is used quite often, but it can be lower of higher than this. The cuvette is placed into the light source. The light source can be an arc lamp or a monochromator.