Both amateur and professional astronomers need to have good spectrometers attached to their telescopes to analyse radiation that comes from planets, stars and other objects in space. These instruments are used to measure visible light by separating it into wavelengths using a prism. Spectrometers are also used to analyse chemical structures or species in substances, so there are many types of spectrometers, including those below.
Optical spectrometers, also known as spectrophotometers, are used to analyse the intensity of light. They break light into wavelengths or frequencies by using a prism or by diffraction. This type of instrument is typically used to study and identify materials.
While they are used in many different fields of study, they are most often found in the field of astronomy. Astronomers use them to analyse radiation to find out its chemical composition. By separating the light, scientists can detect the chemical elements within the objects from which the radiation originated.
A mass spectrometer is used to identify chemical structures of molecules, usually breaking them down into ions. A sample of the substance being analysed is inserted into the mass spectrometer to ionise it and break the sample down by removing the electrons and positively charging the ions. This instrument is used for many purposes and in many industries, including medicine or within the food industry to analyse substances for toxins.
An imaging spectrometer is used to develop spectrally-enhanced images of scenes or objects. Where humans can see visible light in three different colour bands of red, green and blue, this instrument can see many more bands of colours. When certain objects are analysed, they leave what is referred to as spectral signatures that identify the substance or material in an object.
Imaging spectrometers are used in many industries, including geophysical science to find new oil fields. They can be used in agriculture to identify vegetation, or to analyse the physical condition of the Earth. Imaging spectrometers often scan the Earth from orbiting satellites to gather information, such as the condition of the planet and the pollution levels in the oceans or other waterways.
Chemists use IR spectrometers to measure responses from substances or objects when they’ve been exposed to infrared light. The sample is bombarded by IR wavelengths, and the spectrometer measures how well the sample absorbed the IR light. They are usually used to confirm or identify compounds within a substance, because when exposed to the IR light, the spectrum has a unique signature.
Spectrometers not only come in different types, but they are available in different sizes as well. While some of them can be mounted to telescopes, others are loaded into aircraft or are installed at observatories to be used by researchers. These instruments can be purchased from companies specialising in scientific instruments, including those that sell spectrometry equipment. You can usually find spectrometers to fit your needs with different apertures, focal lengths and image resolutions.