The workings of a spectrometer can be broken down into four main parts: the light source, the collimator, the monochromator, and the detector. The light source is the first component of a spectrometer. It works by letting light enter through a slit, then using optics and a grating or prism to separate colors, which a detector measures and displays as a graph. The word “spectrum” refers to the range of wavelengths or frequencies of electromagnetic radiation, which includes visible light, ultraviolet (UV) light, infrared (IR).