Compact confocal sensors
17/10/2019
Precision sensor manufacturer Micro-Epsilon has launched a compact confocal chromatic displacement sensor for high-precision measurements of distance, surface roughness and thickness. The high numerical aperture (NA 0.8) enables thickness measurement of transparent objects with a minimum thickness of 5 µm. Another light-intensive sensor model (NA 0.7) is available for high-speed processes.The IFS2407-0,1 is a compact confocal sensor based on innovative technology that opens up new applications for displacement and thickness measurements. The sensor offers a measuring range of just 100 µm (0.1 mm). This, combined with a high resolution of 3 nm, enables reliable high-precision measurements of transparent layers, such as glass or plastic film/substrates, with thicknesses from just 5 µm.
The sensor offers a large tilt angle, made possible by the numerical aperture, ie the degree of the light rays bundled in the optical system (NA 0.8 or NA 0.7 depending on the sensor model chosen). Combined with a light spot diameter of just 3 µm, the sensor detects the finest of structures and can therefore be used for surface roughness measurements.
The standard version with NA 0.8 is ideal for high-precision measurements of rough surfaces and thin layers. The other light-intensive version (NA 0.7) is suitable for high-speed measurements with a short exposure time and is also suitable for dark surfaces.
Particularly in the automotive industry, extremely high demands are placed on product quality. Confocal chromatic sensors from Micro-Epsilon enable highly accurate inspection of ultra-fine surface structures to be carried out. IFS2407-0,1 sensors can be used for measuring the roughness of brake discs, for example. The disc is smooth, polished and often shiny, with surface structures almost imperceptible to the human eye. These ultra-fine structures become clearly visible only under a microscope. These surface structures are required to create friction and to ensure a high braking force, even after numerous braking manoeuvres.
Another sensor in the confocal range from Micro-Epsilon is the IFS2407/90-0.3.
This has a lateral 90° beam path, which means that it is particularly suitable for special installation scenarios, such as those seen in the inspection of automotive cylinder liners. The axial beam path of the confocal sensors avoids shadowing effects, enabling measurements even in sleeves and recesses. High-precision measurements with tilted objects are also possible.
Confocal chromatic measurement systems are used for precise displacement, distance measurements and intensity evaluation. Based on the determination of the distance, surface topographies of objects can be obtained. Unevenness and scratches influence the degree of reflectance, causing a change in the signal intensity. Therefore, an exact image of the target and its fine structures is produced.
www.micro-epsilon.co.uk
