| 摘要 |
Method and apparatus for inductively measuring the electric conductivity of a fluid, employing an insulated combination, to be placed in the fluid, of a driver transformer and a measuring transformer which are spaced apart, each have an annular (toroidal) core and are electromagnetically coupled by a fluid loop passing through the annular cores, and an electronic driver/measuring circuit. A reference voltage is fed to the driver transformer, and a measuring voltage induced by the current passing through the fluid is taken off the measuring transformer, thus cancelling the effect of the inductance associated with the current passing through the fluid loop. The partial current caused by the said magnetic flux is measured in the measuring circuit, and this is cancelled by an inverse compensation current of equal amplitude being fed back to the measuring transformer. The partial current proportional to the conductivity of the fluid is measured in the measuring circuit by said partial current being readjusted to zero in the measuring transformer by an inverse current of equal amplitude being fed back to the measuring transformer. |
