See what others should not see

Our OY380520 and OY380523 optical diffuse reflection sensors are very special devices because they enable applications to evaluate information or features that should no longer be visible on a product: the optical sensors detect fluorescent material. Not everyone will know what this property is all about straight away. But most people are familiar with the "black light tube", the light source that is often used for show effects.

The light emitted by such tubes is delimited to the non-visible part of UV-A radiation. When this radiation hits fluorescent material, a photophysical process takes place that absorbs part of the radiation energy, while another part is re-emitted. As this part of the light has been shifted in its spectral range during the process, it is visible to the human eye as a light up, as in the black light tube. In this context, it should be mentioned that in general, short-wave visible light is also sufficient to produce the effect of light up, e.g. with a highlighter.

The optical diffuse reflection sensors OY380520 with 150mm switching distance and OY380523 with 300mm switching distance make use of precisely this property: they emit light that they themselves cannot recognize or see. The sensor only switches when the UV light hits fluorescent lumiphore and is then reflected back as visible light. If, for example, a marking on a product is enriched with such substances, it is reliably recognized by the sensors.

The electronics of the sensors are housed in a robust metal housing. The front, behind which the optical components are located, is made of scratch-resistant glass. The feedback from the sensors can be tapped via a PNP or an NPN switching output, which can be easily inverted via a pin on the adjustable M12 connector plug.