26 June 2017 Optical scanner system for high resolution measurement of lubricant distributions on metal strips based on laser induced fluorescence
Author Affiliations +
We present a new optical setup, which uses scanning mirrors in combination with laser induced fluorescence to monitor the spatial distribution of lubricant on metal sheets.

Current trends in metal processing industry require forming procedures with increasing deformations. Thus a welldefined amount of lubricant is necessary to prevent the material from rupture, to reduce the wearing of the manufacturing tool as well as to prevent problems in post-deforming procedures. Therefore spatial resolved analysis of the thickness of lubricant layers is required. Current systems capture the lubricant distribution by moving sensor heads over the object along a linear axis. However the spatial resolution of these systems is insufficient at high strip speeds, e.g. at press plants.

The presented technology uses fast rotating scanner mirrors to deflect a laser beam on the surface. This 405 nm laser light excites the autofluorescence of the investigated lubricants. A coaxial optic collects the fluorescence signal which is then spectrally filtered and recorded using a photomultiplier. From the acquired signal a two dimensional image is reconstructed in real time. This paper presents the sensor setup as well as its characterization. For the calibration of the system reference targets were prepared using an ink jet printer.

The presented technology for the first time allows a spatial resolution in the millimetre range at production speed. The presented test system analyses an area of 300 x 300 mm² at a spatial resolution of 1.1 mm in less than 20 seconds. Despite this high speed of the measurement the limit of detection of the system described in this paper is better than 0.05 g/m² for the certified lubricant BAM K-009.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Philipp Holz, Philipp Holz, Christian Lutz, Christian Lutz, Albrecht Brandenburg, Albrecht Brandenburg, } "Optical scanner system for high resolution measurement of lubricant distributions on metal strips based on laser induced fluorescence", Proc. SPIE 10329, Optical Measurement Systems for Industrial Inspection X, 103292A (26 June 2017); doi: 10.1117/12.2269386; https://doi.org/10.1117/12.2269386

Back to Top