Spectrographic Techniques

Absorption spectroscopy is the measurement of the spectrum of a beam of light before and after interaction with a sample. This technique is used in materials and chemical analysis. The principles are the same as that used in reflection and transmission spectroscopy. The absorption, reflection or transmission of light with a sample can affect the shape of a spectrum as well as its power. This makes materials analysis possible as a material can be identified by its spectral lines. Infra red light is particularly useful in this regard and can be used to pick out the water content of food and pharmaceutical products, plastic type for recycling, together with active ingredient content and concentration in powdered products.