Surface inspection system uses confocal chromatic sensors

In order to record surface topographies, micro-engineering company Certiga - Engineering Solutions GbR is using Micro-Epsilon's optoNCDT 2401 confocal sensors for high-precision measurements. Certiga's KF-30 automatic measurement system has been developed to detect and profile the surfaces of different materials and then display the results three-dimensionally. A typical application for the KF-30 is in dental research, where the system is used to measure the biting surfaces of dental implants and to analyse the resulting abrasions. The system is already being used in this manner at the Munich polyclinic.

The surface to be measured is displayed visually using a CCD camera. The desired area is marked directly in the 'live' image; up to eight surfaces can be measured automatically. The software provided displays the data as a three-dimensional surface. Using the confocal sensor, a resolution of up to 0.12um is achieved. The system is used on surfaces such as plastic, paper, fibre matting, glass and metals.

Extremely high resolutions are possible when using confocal chromatic measurement technology. Resolutions in the nanometre range are typically achieved by expanding the colour spectrum. As the colour, which is in the focal point, is used for distance information, confocal sensors have a very small measuring spot that enables measurements to be made on particularly small objects. Therefore, even very fine scratches on a surface can be measured reliably.

About the confocal chromatic measuring system

Micro-Epsilon's optoNCDT 2401 confocal chromatic measuring system comprises a controller and a sensor. A fibre-optic cable, up to 50m in length, connects these two components. The optoNCDT 2401 has no moving parts and is therefore wear-free. It can also be used in hazardous (ATEX/Ex) environments.

The system consists of an LED-based controller, a fibre-optic cable and one of the sensor heads from the series 2400/2401/2403, or what is claimed to be the world's smallest confocal sensor, the 2402. A free demonstration software tool is included and offers rapid access to system installation and data acquisition.

With transparent materials, a one-sided thickness measurement can be accomplished along with the distance measurement. Since the emitter and receiver are arranged in one axis, shadowing is avoided. In contrast to conventional triangulation sensors, the optoNCDT 2401 system is able to measure in narrow apertures, small gaps and cavities.

Follow the link for more information about Micro-Epsilon's optoNCDT 2401 confocal sensor.