Measurement of scale defects on steel plate in pickling line

This paper describes on-line measurement of pickling grade on a steel plate in a pickling line of a cold rolling mill. Two kinds of light sources such as a red color laser and a white LED were tested to determine which one shows a better performance for pickling degree measurement. Based on the laboratory test results, a proper scheme was designed for a feasibility test. After that, a prototype device for on-line measurement system was fabricated and installed after the pickling line in the cold rolling mill, and the performance was investigated.