Patent ID: 7487052

Claim:
A state detection device characterized by comprising: a measuring tube through which a fluid flows; an exciting unit which applies, to the fluid, a time-changing magnetic field asymmetrical to a first plane perpendicular to an axial direction of said measuring tube; an electrode which is placed on the first plane in said measuring tube to detect a resultant electromotive force of an electromotive force based on a ∂A/∂t component (A: vector potential, t: time) irrelevant to a flow velocity of the fluid and an electromotive force based on a v×B component (v: flow velocity, B: magnetic flux density) originating from the flow velocity of the fluid, the resultant electromotive force being generated by the magnetic field applied to the fluid and a flow of the fluid; and a state quantifying unit which extracts the ∂A/∂t component from the resultant electromotive force detected by said electrode, extracts, from the ∂A/∂t component, a variation factor dependent on a parameter to be detected, and quantifies the parameter on the basis of the variation factor, wherein the parameter is at least one of a characteristic and state of the fluid and a state in said measuring tube.