HARD PARTICLE CONCENTRATION DETECTING METHOD

摘要

Magnetic and counterpart members 12 and 11 are immersed in a liquid which may include hard particles. At least one of the members 12 and 11 is moved while pressed to the other member. The magnetic member 12 is worn by hard particles in the liquid to produce magnetic particles in the liquid. A concentration of the magnetic particles produced is measured and is converted into a concentration of hard particles in the liquid on the basis of a calibration line representing a correlation measured in advance between the concentrations of the magnetic particles and of the hard particles in the liquid. Thus, the concentration of the hard particles in the liquid is detected.