When interacting with different types of substances, light presents different behaviors, which can be used in the quality control of different products.
Propagating in different media and falling on different bodies, light can undergo the wave phenomena of reflection , refraction , diffraction , polarization , etc. The interaction of light with the materials through which it propagates or falls can be used to determine the quality control of industrialized products, for example.
Below, we list three examples of the use of light in product quality control.
light and kaolin
Used in the manufacture of paper, fertilizers, cosmetics and porcelain, kaolin is a kind of clay, whose main component is kaolinite. This material needs strict quality control, such as particle size and brightness.
By shining light on kaolin samples, the percentage of radiation that passes through the material and the color obtained from the phenomenon of polychromatic light scattering are observed. The indices found with the incidence of light on the material determine the quality and purity of the substance.
The light and color of chocolate
Errors in important phases of the chocolate production process can cause a change in the color of the substance, thus, the quality of the product, in addition to other factors, is related to its color .
the refractometer
Refractometers are equipment used to determine the refractive index of light in substances in the liquid phase. The device emits a ray of light that strikes the substance and undergoes refraction , a phenomenon that determines the change in the direction of propagation and in the speed of light, when it changes its propagation medium. From the angles of incidence and refraction of light, the refractive index of the substance can be determined.
Changes in the density of substances cause changes in the value of the refractive index, therefore, the determination of this magnitude becomes important to guarantee the quality of these products.
When using the refractometer to measure the refractive index of a juice, for example, a predetermined value of quality is expected. If the sugar content is outside the normal range, the refractive index of the juice will not have the ideal value, and its quality will be compromised.
