THE light is electromagnetic wave, transverse and three-dimensional. As it is of the electromagnetic type, it does not need a propagation medium, and its speed in vacuum is 3 x 108 m/s. Light waves are the product of the joint propagation of a electric field it is a magnetic field, variables in space.
Light is a type of electromagnetic wave, transverse and three-dimensional
When interacting with different materials, light can suffer reflection, refraction, diffraction, polarization, etc. These forms of interaction of this wave with materials can be used to determine the quality of some products. Several industries, from food to mining, use light to control the quality of their production.
Below are three examples of the use of light in determining the quality of substances.
The light and color of chocolate
The goodness of chocolate, among other factors, it depends on the color of this substance. Errors in certain phases of its production can cause changes in this characteristic.
In addition to being carried out by observation, the analysis of the color of chocolate can be carried out using equipment. By shining light on this substance, the color of the reflected light rays can be analyzed, thus, it is possible to accurately define the color of the substance and guarantee its quality.
the light and the kaolin
Kaolin is a type of clay used in the manufacture of products such as paper, cosmetics and porcelain. This material has kaolinite as its main component and needs strict quality control as to particle size and brightness.
By shining light on kaolin samples, the percentages of light that pass through the material and the colors that arise from the light scattering by him they are used as parameters to determine the purity of this substance.
the refractometer
O refractometer is a device used to determine the refractive index of a substance in the liquid phase. When emitting light on the liquid, the equipment analyzes the refraction suffered by the light ray incident and, from the angles of incidence and refraction, determines the index of refraction of this substance.
When using the refractometer to measure the refractive index of a juice, for example, a predetermined value is expected, which can characterize the good quality product. Changes in sugar content can change the substance density, which, consequently, changes the value of the refractive index.
By Joab Silas
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/controle-qualidade-com-uso-luz.htm