Improper oil film layer distribution or even dry stripes on a metal strip creates problems in the forming process. Therefore an online measuring system is needed for the supervision. The AMEPA OFM system is the first system enabling online oil film measurement and automatic classification of the strip.
Current tools to measure oil film thickness on a steel strip are limited to an offline analysis in a laboratory or to hand-held devices. Offline measurements cannot provide adequate information, thus any oiling problems are detected too late in the production process causing loss of both time and money. The Oil Film Measurement System OFM solves this process-measurement need. It fulfils operational requirements by providing an online tool for accurate measurements and offers a continuous documentation of quality. The OFM System provides:
The OFM technology takes advantage of Lambert Beer‘s light absorption law. It states that the thickness of an oil film is directly proportional to the extinction of light (image 1). As the oil strip surface is illuminated, part of the light is reflected by the metal. On its path, the light penetrates the oil film twice and specific wavelengths are partially absorbed by the oil.
In practice, special lamps are used as light sources. Only a small number of characteristic wavelengths in the mid infrared range (MIR) of the electromagnetic spectrum are examined by the detector (image 2). AMEPA‘s OFM System has the following features: