Spectrometer

A spectrometer is an apparatus for displaying a spectrum. In contrast to a spectroscope, it offers the possibility to measure the spectra.

A spectrum intensity as a function of wavelength, frequency, or energy - in the case of elementary particles, atoms or ions - the mass. Due to the wave -particle duality, these sizes are often equivalent.

In optical spectrometers, the differentiation of the wavelengths of the radiation to be analyzed is often generated by the direction of deflection by means of refraction in a prism or through diffraction by a grating. It is also possible to determine the frequency components in an interferometer using a Fourier analysis (FTIR ) spectrometer.

At particle and mass an electrical ( Stark effect ) and / or magnetic field ( Lorentz force ) and the Zeeman effect used for the analysis. Especially for heavy particles but can also be the time of flight and thus the velocity of the particles are measured.

A simple optical spectrometer (see figure at right) has only a few ingredients:

• A broadband light source S;
• A gap F1 in order to obtain a linear light source;
• Between a condenser ( not in picture), which reflects the light source on the slit;
• A lens L1, the parallelized the divergent incident light;
• A sample space with holder for filters or cuvettes ( in the picture is the light source, the object of investigation )
• A light- refracting prism P ( or diffractive grating ) in order to deflect the radiation to be analyzed;
• A second lens L2 which images the entrance slit in a plane on F2;
• There an exit slit S2 or a position-sensitive detector (the latter is in the image armed with ocular eye).

In the case of an output gap S2 and the detector behind it are moveable and sit on a scale (see goniometer ).