Protective coatings are commonly applied to automobiles, aircrafts, ships, railways,furniture, bridges, concretes, architectural constituents, industrial installations, and many other products that we encounter on a daily basis. Coating application in many of these products is primarily implemented to provide protection against harsh environments such as UV light, extreme temperatures, acid, alkali, salt, water, and so forth, and to improve the aesthetic appearance of finished products.A wide variety of coating formulations exist in the market; their use depends on the performance requirement of the final product. Coatings may be applied to the products as a primer basecoat, a mid-coat, or as the topcoat. For example, polyurethane coating is applied on top of epoxy primer coating to prevent the discoloration of epoxy from UV and to provide the specified color and sheen. Agilent 4300 手持式 FTIR 光譜儀