Confocal sensors in hybrid technology

The new optoNCDT confocal chromatic sensor from Micro-Epsilon combines the benefits of two successful confocal design concepts. With an external diameter of 8mm, the sensor is compact and slim, similar to the optoNCDT 2402 range of miniature sensors. However, due to its larger digital aperture, the sensor can receive significantly more reflected light than the smaller, 4mm diameter version.

In the new sensor an ancillary lens is positioned in the light path before the thin gradient index lens with its exactly adapted refractive index profile. Due to its greater divergence, the so-called relay lens enables significantly more reflected light from the target to be detected. This is particularly beneficial if the sensor has to be tilted or if the target is non-planar, so that the reflected light is only reflected back by an angular deviation in the sensor. In this way, due to its larger opening angle, the optoNCDT 2403 can perform more stable measurements on poorly reflecting and tilted surfaces than the optoNCDT 2402. The relay lens also increases the base distance of the sensor, which means it can be placed further away from the measurement object.

Typical applications for the new sensor are installations in which space is restricted and where the required base distance is not ideal for reflecting target surfaces. For the launch, four sensor versions are available with measuring ranges between 0.4mm and 10mm and axial beam output.