The difference between reflection and remission is how light rays are returned when they meet a surface:
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Reflection describes the impact of light rays on a surface, which then bounces the rays back in the same direction.
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Remission describes the scattering of light rays in all directions when they hit non-reflective surfaces.
Gloss sensors are particularly useful in the quality control of shiny or reflective surfaces. They capture materials where the degree of gloss or reflective properties are important, such as foils, paints, seal labels, hologram stickers or tamper-evident labels.
Gloss sensors have a linear optic because they work with a laser diode without additional lenses. This creates an oval light spot that allows the sensor to detect the reflection over a larger area.
To ensure a reliable measurement, it is crucial that the sensor is mounted perpendicular (i.e. at a 90-degree angle) to the surface of the object. This ensures that the reflection is correctly fed back to the receiver. Sensors mounted at an angle could lead to inaccuracies.
Yes, gloss sensors are less sensitive to vibrations. The reason for this is the large aperture angle of the gloss sensors. A wider aperture angle means that the sensor is able to receive light from a larger area, making it less susceptible to small changes in the object’s position or vibrations.
The choice between a gloss sensor and a contrast sensor depends heavily on the specific application and the properties of the object to be tested. Gloss sensors are mainly used to check the surface finish of objects or the presence of shiny films or labels. Contrast sensors, on the other hand, are often used to position objects, detect colors and identify markings on packaging or printed matter.
