In-Situ-detection of cooling lubricant residues on metal surfaces using a miniaturised NIR-LED-photodiode-system

Because of the flexibility of this testing method concerning punctual and surface measurements as well as the low input in apparatus, this testing method, as described in the present paper, offers the possibility to considerably reduce the reject rate of cleaning-sensitive manufacturing in metal working by in-situ detection of oil-based contamination films. The developed in-situ detection represents an efficient and economic method of reproducible testing surface cleanliness especially for metal-cutting, which due to its partly rough and changing surfaces has not been possible up until now. In manufacturing processes in which the quantifiability of contamination films within defined limits are of interest for subsequent processes, radiation sources have to be used where the wavelength lies within the range of higher absorption coefficients.