Magnetic sensor and method for quantitatively identifying magnetic hysteresis loop characteristics of magnetic code

A method for quantitatively identifying magnetic hysteresis loop characteristics of magnetic code using magnetic sensor, comprising the steps of:

• completing the whole or part of a hysteretic loop process while a magnetic code passes by the surface of the magnetic sensor, identifying magnetic hysteresis loop characteristics of the magnetic code, wherein:
• the identifying the magnetic hysteresis loop characteristics of the magnetic code comprises identifying soft magnetism and hard magnetism properties of the magnetic code on the magnetic hysteresis loop characteristics of the magnetic;
• code as well as quantitatively defining coercive force, square degree and reverse magnetic field distribution of the magnetic code;
• the identifying the soft magnetism and hard magnetism properties specifically refers to judging whether the magnetic code is hard magnetism having a coercive force greater than the magnetic field of the magnet according to that whether a signal of a single magnetic code is one single-edge peak;
• the quantitatively defining the coercive force of the magnetic code specifically refers to calculating a wave amplitude ratio between different wave peaks of the signal of each single magnetic code sensed by magnetic sensitive units so as to weigh and quantitatively define the coercive force of the magnetic code;
• the quantitatively defining the square degree and the reverse magnetic field distribution characteristics of the magnetic hysteresis loop of the magnetic code specifically refers to calculating a ratio between time widths of a signal waveform of a single magnetic code sensed, and using the ratio to weigh and quantitatively define the square degree of the magnetic hysteresis loop of the magnetic code and the reverse magnetic field distribution;
• a specific process for identifying the soft magnetic and hard magnetic properties of the magnetic code comprises:
• when only one single-edge signal peak appears in the signal displayed by the single magnetic code, identifying whether the magnetic code is hard magnetism having a coercive force greater than the magnetic field of the magnet;
• otherwise, identifying the magnetic code as soft magnetic;
• a specific process for identifying the coercive force of the magnetic code comprises:
• when two wave peaks appear, a ratio obtained via dividing the peak value of the latter peak by the peak value of the former peak reflects the forward coercive force of the magnetic code;
• when the ratio is 1, the corresponding coercive force of the magnetic code is zero;
• when the ratio is 0, only one peak exists at the moment, and the corresponding coercive force of the magnetic code is greater than the maximum lateral magnetic field of the magnet, so that the coercive force cannot be reversed by the magnetic field of the magnet;
• a wave amplitude ratio corresponding to the coercive force between the two is between 1 and 0;
• the wave amplitude ratio is more closer to 1 when the coercive force is smaller, and the wave amplitude ratio is more closer to 0 when the coercive force is larger;
• when three wave peaks appear at the same time, a ratio obtained via dividing the peak value of the first peak by the peak value of the second peak reflects the negative coercive force of the magnetic code;
• the ratio is more closer to 0 when the coercive force is smaller, and the ratio is more closer to 1 when the coercive force is larger;
• and a ratio obtained via dividing the peak value of the third peak by the peak value of the second peak reflects the forward coercive force of the magnetic code;
• the wave amplitude ratio is more closer to 1 when the coercive force is smaller, and the wave amplitude ratio is more closer to 0 when the coercive force is larger;
• and
• a specific process for quantitatively defining the square degree and the reverse magnetic field distribution characteristics of the magnetic hysteresis loop of the magnetic code comprises:
• calculating the time width ratio of a waveform interval according to the signal displayed by each single magnetic code, wherein:
• when only one signal peak exists, the magnetic code is hard magnetism that cannot be reversed by the magnet, and the reverse magnetic field distribution cannot be identified;
• the square degree of the magnetic code is quantitatively expressed by a ratio between a time difference when the peak falls back from a peak value to 90% of the peak value and the half-width of the peak;
• and
• when two or three signal peaks appear, a ratio between a time difference when a second peak from the last falls back from a peak value to 90% of the peak value and the half-peak width of the peak is the magnitude of the square degree;
• and a ratio between a time difference when the peak returns to zero from 50% of the peak value and the half-peak width of the peak is the reverse magnetic field distribution.