Patent ID: 7496455
Filing Date: 2009-02-24
Classification: G01F

Abstract:
1. An electromagnetic flowmeter characterized by comprising: a measuring tube through which a fluid to be measured flows; an exciting unit which applies a time-changing magnetic field to the fluid; an electrode which is placed in said measuring tube and detects a resultant electromotive force of an electromotive force based on a ∂A/∂t component (where A is a vector potential and t is a time) which is generated by a magnetic field applied to the fluid and a flow of the fluid and is irrelevant to a flow velocity of the fluid and an electromotive force based on a v×B component (where v is a flow velocity and B is a magnetic flux density) originating from the flow velocity of the fluid; a signal conversion unit which extracts the ∂A/∂t component from the resultant electromotive force; and a flow rate output unit which extracts only the v×B component by removing the extracted ∂A/∂t component from the resultant electromotive force, and calculates the flow rate of the fluid from the v×B component.