A spectrometer is a device for displaying a spectrum . In contrast to a spectroscope , it offers the possibility of measuring the spectra.
A spectrum is the intensity as a function of the wavelength , the frequency , the energy or - in the case of elementary particles, atoms or ions - the mass .
Because of the wave-particle dualism , these quantities are often equivalent .
At frequencies well below light, high-frequency technology offers electronic options for measuring spectra, see spectrum analyzer .
In the case of optical spectrometers , the differentiation of the wavelengths of the radiation to be analyzed is often generated by directional deflection by means of refraction in a prism or by diffraction on a grating . It is also possible to determine the frequency components in an interferometer using a Fourier analysis ( FTIR spectrometer ).
In particle beams and mass spectrometry , an electric ( Stark effect ) and / or magnetic field (Lorentz force) and the Zeeman effect are used for analysis. Especially with heavy particles, the flight time and thus the speed of the particles can also be measured.
A simple optical spectrometer (see figure on the right) has only a few components:
- a broadband light source S;
- a gap F1 for receiving a line-shaped light source;
- in between a condenser (not in the picture) which images the light source onto the slit;
- a lens L1 which parallelizes the divergent incoming light;
- a sample space with a holder for filters or cuvettes (in the picture the light source is the object to be examined)
- a refractive prism P (or diffractive grating) to deflect the radiation to be analyzed ;
- a second lens L2 that images the entrance slit in a plane at F2;
- there an output slit S2 or a spatially resolving detector (the latter is an eye armed with an eyepiece in the picture).
In the case of an exit slit, S2 and the detector behind it are movable and sit on a scale (see goniometer ).
- The Optics of Spectroscopy Tutorial
- Spectrometer (accessed July 20, 2017)