USB 2.0 industrial camera as optical component in white light interferometer

A white light interferometer consists of several components: a light source, a beam splitter, a reference mirror and a camera. The light source is splitted up by a beam splitter, whereas one beam is redirected and reflected to the reference mirror, the other to the object, which will be measured. Both reflected beams interfere with each other to form an interference image. The distance between reference mirror and beam splitter makes the fictitious reference level from beam splitter into the direction of the object.
By the use of small object shiftings in z direction, the interference image is changing. This is noticed by the camera in the form of brightness fluctuations. In doing so, you have to notice that an interference pattern will only occur, if the distance difference between reference mirror and object surface is smaller than the coherence.

The software evaluates the inteferences and assignes the values of the heights to the accordant pixels. You will receive an image of the heights of the object with a very small error of measurement. The white light interferometer combines the advantages of tactile sensors with the advantages of optical sensors: high measuring accuracy with high data rates.

3D-Shape uses MATRIX VISION's industrial USB 2.0 camera mvBlueFOX as the camera for the µKORAD3D. Beside the good price-performance-ration, the quality and the specification of camera satisfied the decider. The whole camera series of MATRIX VISION have a similar control as the solution of 3D-Shape, the integration has proved to be easy and the promise that the camera will be available for long time, makes a contribution to the decision for the camera.

Application areas of the white light interferometer

There are many possible applications for the white light interferometer. Both for sample surveys and for 100% quality checks the measurement system is suited for. For the interpretation, however, an area is available in contrast to the tactile pendants, which only shows a profile line as a result. During quality checks of the surface of an electronical component for example, the white light interferometer inspects the object and names diameter and height using the resulting measurement data. A further application is the roughness measurement of milling grooves on metal surfaces along profile lines. Additionally the laminar roughness parameters can be calculated, too.