Luminescence sensors send out UV light with a wavelength of 375 nm. Should this light come upon a luminescent material, this will light up in the visible wavelength range (420 to 750nm) according to the luminescent substance used. This fluorescence effect uses the luminescence sensors e.g. for the detection of markings which are not visible in daylight.
Luminescent substances can be applied to almost anything (e.g. labels and cartons), and can be added to many substances (e.g. ink, oil and grease). It is possible to select the wavelength range, i.e. the colour, that the sensor detects by using optical filters.
Application examples:
- Presence control for labels and instruction leaflets
- Alignment of spray cans without optically visible markings
- Monitoring the authenticity of products (plagiarism detection)
- Control of saws in the wood industry