APPARATUS FOR MEASURING THE DRAFT OF A ROLLED STEEL.

摘要

Appts. for measuring draft of rolled steel by calculations based on the speed of magnetic marks determined by magnetisers and magnetic mark detectors at the entry and exit sides of rolls includes counters actuated by detector signals and whose action is started by a common signal that also actuates the magnetisers, an AND gate connected between the entry side counter and a comparator of the entry side detector and a gate signal generator that receives exit side detector output via an exit side comparator and produces signals to open the AND gate. The entry side counter is stopped by the AND gate output and the exit side counter by output of the exit side detector's comparator and the counter contents are read and used to calculate magnetic mark displacement speed. The appts. also includes circuit elements for automatically varying comparator comparison levels to counter noise effects.