MAGNETIC SUBSTANCE CONCENTRATION MEASURING APPARATUS, DETERMINATION SENSITIVITY IMPROVING METHOD, ZERO-POINT COMPENSATION METHOD, AND ZERO-POINT CORRECTION METHOD

摘要

A magnetic substance concentration measuring apparatus, a determination sensitivity improving method, a zero-point compensation method and a zero-point correction method wherein the concentration of magnetic substance in a fluid is continuously measured, thereby improving determination sensitivity of magnetic substance. There are included an actual measurement LC oscillation circuit (1) that has a first coil (5) disposed in the vicinity of or within a fluid so as to determine a change of a frequency corresponding to the concentration of magnetic substance in the fluid; a correction LC oscillation circuit (2) that has a second coil (6) disposed at such a position that is not affected by the magnetic substance in the fluid or at such a position that is little affected by the magnetic substance in the fluid. A difference of measurement data is determined from the oscillation frequencies of the actual measurement LC oscillation circuit (1) and correction LC oscillation circuit (2), and disturbance is removed. The amount of a change caused by the magnetic substance is compared with the measurement data difference that is used as a reference, thereby improving the determination sensitivity of magnetic substance.