Detection of Knotholes in the Wood Industry with Luminescence Sensors
In the wood industry, it is crucial to identify knotholes in wooden boards so that they can be removed during cutting. To ensure that the valuable raw material is not damaged or contaminated, the knotholes are marked with luminescent substances such as chalk or ink, which are not visible in normal light. A luminescence sensor detects these markings before cutting regardless of the color or shape of the wood surface. The saw is then controlled with the switch signal, the knotholes are precisely cut and waste is thus reduced.
Luminescence sensors emit UV light at a certain wavelength. If the emitted light strikes a luminescent object, it reflects within a visible wavelength range in accordance with the luminescent substance mounted. The sensors use this effect to make markings on labels visible, for example.