The German sensor-maker Micro-Epsilon has launched what it claims is the world’s first triangulation position sensor that uses blue lasers rather than red. It says that the optoNCDT 1700BL sensors offer significant benefits, especially when measuring the position or displacement of hot metals, as well as organic materials such as skin, foods, plastics, veneers and wood.

When used to monitor red, glowing objects, conventional red lasers suffer from signal interference from the object’s surface. However, the blue laser works at a wavelength far from the red part of the spectrum, making it easier to filter this light from the object. The blue laser measures well on both glowing metals and ceramics.

The blue laser also has a lower intensity spot than red lasers and does not penetrate into translucent objects such as organic materials, paper and plastics. It therefore offers more stable, precise measurements on these targets that conventional red laser sensors have difficulty measuring.

The laser projects a point of light onto the surface of the target object. This is reflected onto a CCD array. If the target moves, the change in the reflected light is sensed and analysed to calculate its position.

There are six versions of the blue laser sensors with measuring ranges from 20mm to 1m. Maximum linearity is 16μm and maximum resolution is 1.5μm at 2.5kHz.