Residual magnetism reduction method of Omnia plate

摘要

PROBLEM TO BE SOLVED: To simply reduce the influence of residual magnetism on the OMNIA board. ;SOLUTION: An OMNIA board 10 has an OMNIA truss reinforcement 14 including an upper chord 11, a lower chord 12 and a lattice bar 13 disposed between the chords, a magnetization pattern of residual magnetism of the upper chord 11 and the magnetism distribution at a designated height are measured, and with a current-carrying cable 20 arranged along the upper chord 11, a direct current is supplied to the current-carrying cable 20. Thus, the residual magnetism can be applied in the direction of canceling magnetic field of a required height to the upper chord 11 by formed lines of magnetic force.;COPYRIGHT: (C)1999,JPO