Linear measurement of steel tubes in motion by combining magnetic imprinting with a wheel counter

A method of measuring the throughput of steel tube or bar from a cold rolling mill or on a conveyor is described. Magnetic spots are created at 1 ft intervals along the extensive length: these are counted, thereby recording the aggregate footage. A wheel of 1 ft circumference is also held in contact with the material and this is used to measure that fraction of a foot not measured by the foot counter. The combination of footprints and wheel makes for an accurate system of measurement at high speeds where the surface conditions of the steel are such that a simple wheel and counter would be highly inaccurate due to slip. Laboratory experiments are described showing the potential accuracy of the system. A proposed application for the measurement of steel tubes is described and its probable performance evaluated.