METHOD FOR SENSING DEFECT OF MEASURED VALUE OF SPONTANEOUS EMISSION-TYPE STEEL PLATE WIDTH METER

摘要

PURPOSE:To sense a defect of a measured value of plate width caused by drop in temperature of a steel plate width end in measuring the plate width of the steel plate being hot-rolled between rolling stands by a spontaneous emission type steel plate width meter which utilizes spontaneous emission (infrared radiation) of the steel plate. CONSTITUTION:Plate width of a steel plate S being hot-rolled is measured by a spontaneous emission type steel plate width meter 4 placed between rolling stands 1, 2 and a lower light source type steel plate width meter 7 which is placed at an outlet side of a final rolling stand and is placed under a steel plate path line respectively so as to obtain difference in measured width values obtained by both width meters 4, 7. On the hand, a value of change in width of the steel plate S due to rolling from the self-illuminating steel plate width meter 4 to the lower light source type steel plate width meter 7 is calculated based on rolling conditions. Deviation between the difference in measured width values and a calculated change value of width is obtained, and when the deviation is larger than a set value, the measured width value obtained by the spontaneous emission steel plate width meter 4 is determined to be defective.