Eddy current apparatus and method for controlling a rod mill on the basis of faults detected per unit time

摘要

Method and apparatus for monitoring a rod mill and flexible wire drawn and annealed from a stiff coil of rod in the rod mill are disclosed. The fault signals provided by an eddy-current tester are counted on a per unit time basis in order to permit the detection of rod mill problems before serious deterioration of the mill occurs. This is accomplished by direct observation of an increasing rate of fault signal occurrence. A totalized fault signal count is also provided to aid in detecting low quality wire. This is accomplished by direct observation of uniformly high levels of fault signals. A control function is disclosed whereby the rod mill is shutdown in the presence of a high rate of increase in fault signal occurrences. A "change coil" message may be sent upon detecting uniformly high levels of faults. Fault signals are stored and identified for purposes of traceability. The invention is broadly applicable in other eddy-current testing contexts, that is, other than that context specifically disclosed for the best mode embodiment.