| 摘要 |
A flowmeter for measuring the velocity of a fluid produces magnetic field transverse to the direction of fluid velocity thereby inducing a voltage potential in the fluid. The magnetic field may be produced using either electromagnets or permanent magnets. Two primary electrodes in electrical contact with the fluid, spaced apart along a first line transverse to the direction of the magnetic field and transverse to the direction of the fluid velocity sense the induced voltage potential and a background voltage across the fluid. Two secondary electrodes in electrical contact with the fluid, spaced apart along a plane parallel to the direction of the magnetic field and parallel to the direction of the fluid velocity, sense the background voltage across the fluid. A signal processor, responsive to the primary and secondary electrodes, generates a velocity signal representative of the magnitude of the velocity of the fluid. A magnetic sensor senses the magnitude of the magnetic field across the fluid and the signal processor corrects the velocity signal for any fluctuations in the magnetic field. |
