Reliable detection of transparent objects

STM Sensor Technologie München GmbH: Detecting the presence of transparent bodies made of injection-moulded plastics or glass often proves to be surprisingly difficult. Bothersome effects such as total reflection, diffusion or light conduction, which can make some optical signals unanalysable, frequently arise at the boundary surfaces.

Optical detection of transparent surfaces, regardless of whether they are flat or curved, requires a very high-quality light beam exactly matched to the respective measurement situation. Sensors in the nanoSPOT® line or the DKM60R micro-laser light barrier in the MICROmote® line deliver the required precision.

Application example: well plates The correct light beam dimension and the optimal angle of impact are the deciding factors on whether a detection signal will be robust or marginal.

Application example: stored substrate carriers. Due to the dense packing and the very different quality of the edges, undesirable reflections or deflection effects can arise. Even small changes in the geometry can have a drastic influence on the reliability of the entire detection.

In each of the above application examples, the ideal solution is a parallel light beam with a small diameter and low light scatter. Several sensors in the MICROmote® line meet this requirement. The fact that they are also particularly small is an additional advantage.