METHOD AND APPARATUS FOR MEASUREMENT OF FLOW VELOCITY

摘要

PROBLEM TO BE SOLVED: To obtain a method and an apparatus in which the flow velocity of a moving conductive object to be measured is measured without being influenced by a temperature drift when the flow velocity of the moving conductive object to be measured is measured on the basis of a detected magnetic-field signal in such a way that a magnetic field is excited on the object to be measured and that an induced magnetic field by the object to be measured is detected. SOLUTION: A set measuring time T1 in which a continuous measurement is finished before a change in an offset portion generated in a magnetic-field signal exceeds a target resolution since the continuous measurement is started in advance is set. In addition, an adjusting time T2 in which an offset portion generated in the magnetic-field signal immediately after the T1 expires is adjusted to zero is set. The measuring time T1 and the adjusting time T2 are generated alternately. A continuous measuring operation and an offset-portion adjusting operation are repeated.