JP4805631B2 - Magnetic body analyzing apparatus and magnetic body analyzing method - Google Patents

Description

  The present invention relates to an apparatus for quantitatively measuring the amount of a magnetic substance contained in a measurement object and a magnetic substance analysis method applied to the apparatus.

Currently, in fields such as medical diagnosis and environmental measurement, there is a demand for measuring a minute amount of magnetic substance contained in a substance. In such measurement, since high detection accuracy of the magnetic material is required, it is particularly important to obtain a high S / N ratio (Signal to Noise) by removing the noise component of the detection signal.
Signal noise is caused by various causes, and some are caused by the measurement environment. Such noise is referred to as environmental noise. For example, hum noise generated due to the presence of a high frequency power supply in the measurement environment, and motor noise and vibration noise generated due to the presence of a motor are collectively referred to. Among them, hum noise is known to be a noise in which a periodic signal of 50 Hz to 60 Hz is mixed in a detection signal, and is particularly a noise having a great influence on signal detection. The hum noise is also called power supply noise or humming noise.

The hum noise is caused by a change in level caused by an AC power supply placed in a signal detection environment. For this reason, the conventional measurement of the amount of magnetic material has a problem that the reproducibility is lowered due to hum noise depending on the arrangement of the power supply in the measurement environment and the on / off state, and the reliability of the measurement result is low.
In order to solve such a problem, a configuration is known in which specific frequency noise is removed by a method called phase detection typified by measurement using a lock-in amplifier. In the phase detection method, a signal to be detected is modulated at a frequency that is greatly different from the frequency of noise. Then, by extracting only the signal synchronized with the modulated frequency, noise and the signal that is the object of detection are separated from the detection signal.

Since such a method using phase detection can easily modulate a detection signal in the field of optics, a target signal can be detected with high accuracy.
By the way, in the measurement of the amount of magnetic material, the frequency of the detection signal is generally modulated by modulating the magnetic field used in the magnetic sensor. As a conventional example of the method for measuring the amount of magnetic material performed by modulating the magnetic frequency, for example, Patent Document 1 can be cited. In the invention described in Patent Document 1, the detection signal of the magnetic substance amount is obtained with a high S / N ratio by modulating the frequency of the detection signal using an electromagnet and removing hum noise.
US Pat. No. 6,046,585

However, since the invention described in Patent Document 1 modulates the frequency of the detection signal using an electromagnet, the coil of the electromagnet generates heat due to the inductance, which may damage the coil.
Further, the modulated signal increases as the applied magnetic field strength increases, but when the magnetic field strength is increased by the number of turns of the coil, the amount of heat generation also increases. For this reason, in the invention of Patent Document 1, an electromagnet having an annular core type with a narrow gap is used, and a magnetic field is generated in the gap. And the magnetic body used as a to-be-measured object is set | placed in this gap, and the magnetic body amount of a magnetic body is measured.

For this reason, the invention of Patent Document 1 has a disadvantage that the size of the measurable object to be measured is limited and the measurement versatility is low.
The present invention has been made in view of such a problem, and since it is difficult to be affected by hum noise, it is possible to measure the amount of magnetic material with high accuracy and to have high versatility in measurement. An object of the present invention is to provide a body analyzing apparatus and a magnetic body analyzing method applied to the apparatus.

In order to solve the above-described problems, a magnetic substance analyzer of the present invention includes a first sensor unit that can detect the strength of a magnetic field, and is electrically connected to the first sensor unit at a predetermined interval. A second sensor unit capable of detecting the intensity of the installed magnetic field, the first sensor unit, and at least the first sensor unit of the second sensor unit passing through a range in which a magnetic field change can be detected. An object moving means for moving the object to be measured, and the object to be measured within a range in which only the first sensor unit can detect a magnetic field change when the object to be measured is moved by the object moving means. includes a signal obtained from the first sensor unit in the period, a signal processing circuit for differential operation on the signal obtained from the second sensor unit through, the by the signal processing circuit Includes a magnetic material amount detecting means for detecting such information on the magnetic body of Jobutsu, wherein the first sensor unit and the second sensor unit, semiconductor magnetic electrical characteristics change depending on the magnetic field strength a resistance element, a magnetic field generating means for applying a static magnetic field to the semiconductor magneto-resistive element and the object to be measured, characterized Rukoto with a to.

  According to such an invention, the first sensor unit and the second sensor unit that can detect the strength of the magnetic field can be electrically connected to each other and arranged at a predetermined interval. In addition, the device under test can be moved through a range in which at least one of the first sensor unit and the second sensor unit can detect a magnetic field change. Furthermore, when the object to be measured is moved, information relating to the amount of magnetic material of the object to be measured can be detected using the signal obtained from the first sensor unit and the signal obtained from the second sensor unit. .

  For this reason, one of the first sensor unit and the second sensor unit detects a signal including a signal related to the amount of magnetic material of the object to be measured, and the other detects a noise signal serving as a detection background. Can do. Then, it is possible to separate a signal relating to the amount of magnetic material of the object to be measured and a noise signal from the signal detected by comparing both signals.

Since the present invention is hardly affected by hum noise, the amount of magnetic material can be measured with high accuracy.
In addition, according to the present invention, the object to be measured is moved through a range in which at least one of the first sensor unit and the second sensor unit can detect a magnetic field change, and the amount of magnetic material of the object to be measured is Is detected. For this reason, there is no restriction | limiting in the shape and size of the to-be-measured object which can be analyzed, and the magnetic body analyzer which has high versatility of a measurement can be provided.

Further, according to the invention as this, to magnetize the object to be measured by applying a static magnetic field in the object to be measured is changed in accordance with applied magnetic field to the magnetic field sensor unit to the magnetic amount. Furthermore, a change in the magnetic field can be detected by a change in the electrical characteristics of the magnetic field sensor unit. For this reason, it is possible to detect the amount of magnetic substance of the object to be measured with a relatively simple configuration.
Moreover, according to such an invention, the structure suitable for outputting the difference of the output signal of a 1st sensor unit and the output signal of a 2nd sensor unit is realizable.

In the magnetic substance analyzer of the present invention, the predetermined interval between the first sensor unit and the second sensor unit is 1 mm or more and 50 mm or less. To do.
According to such an invention, the first sensor unit and the second sensor unit are separated from each other by an appropriate distance that is equal in hum noise and that is not affected by the magnetic field generated by the other magnetic field generating means. Can be installed.

In the magnetic body analyzer of the present invention, the predetermined interval is 5 mm or more and 30 mm or less.
According to such an invention, the first sensor unit and the second sensor unit are separated from each other by a more appropriate distance that has the same hum noise and is not affected by the magnetic field generated by the other magnetic field generating means. Can be installed.
In the magnetic material analyzing apparatus of the present invention, the magnetic field sensor unit is a semiconductor magnetoresistive element.
According to such an invention, the magnetic substance analyzer of the present invention can be realized by using a configuration that is easy to obtain, has a relatively simple configuration, and has a high detection accuracy.

Moreover, the magnetic substance analyzer of the present invention is characterized in that the first sensor unit and the second sensor unit are connected in a differential manner.
According to such an invention, a configuration suitable for outputting the difference between the output signal of the first sensor unit and the output signal of the second sensor unit can be realized .

The magnetic substance analysis method of the present invention comprises a semiconductor magnetoresistive element whose electrical characteristics change according to the magnetic field strength, and a magnetic field generating means for applying a static magnetic field to the semiconductor magnetoresistive element and the object to be measured. a first sensor unit, and a said magnetic field generating means and the semiconductor magnetoresistive element, said first sensor unit and is electrically connected, and separating the first sensor unit by a predetermined distance established with Of the first sensor unit, the first sensor unit, and the second sensor unit to be moved through a range in which at least the first sensor unit can detect a magnetic field change. includes a measurement object moving means, a signal obtained from the first sensor unit, a signal processing circuit for differential operation on the signal obtained from the second sensor unit, the signal processing A magnetic analysis method applied to the magnetic analyzer and a magnetic material amount detecting means for detecting such information on the magnetic body of the object to be measured by the circuit to be measured by the measurement object moving means A measured object moving step for moving an object, and a period during which the measured object passes through a range in which only the first sensor unit can detect a magnetic field change when the measured object is moved in the measured object moving step. wherein the signal detecting step of detecting an output signal by the first output signal by the sensor unit and the second sensor unit, output by said detected first sensor unit in the signal detecting step The magnetic substance amount detection for detecting information relating to the magnetic substance amount of the object to be measured by taking the difference between the obtained signal and the signal output by the second sensor unit A step, characterized in that it comprises a.

  According to such an invention, the first sensor unit and the second sensor unit that can detect the strength of the magnetic field can be electrically connected to each other and arranged at a predetermined interval. Further, the object to be measured can be moved through a range in which at least one of the first sensor unit and the second sensor unit can detect the magnetic field. Furthermore, when the object to be measured is moved, information relating to the amount of magnetic material of the object to be measured can be detected using the signal obtained from the first sensor unit and the signal obtained from the second sensor unit. .

  For this reason, one of the first sensor unit and the second sensor unit detects a signal including a signal related to the amount of magnetic material of the object to be measured, and the other detects a noise signal serving as a detection background. Can do. Then, it is possible to separate a signal relating to the amount of magnetic material of the object to be measured and a noise signal from the signal detected by comparing both signals.

Since the present invention is hardly affected by hum noise, the amount of magnetic material can be measured with high accuracy.
In addition, according to the present invention, the object to be measured is moved through a range where at least one of the first sensor unit and the second sensor unit can detect the magnetic field, and the amount of magnetic substance of the object to be measured is reduced. To detect. For this reason, there is no restriction | limiting in the shape and size of the to-be-measured object which can be analyzed, and the magnetic body analysis method with the high versatility of a measurement can be provided.

  The magnetic body analyzer of the present invention can detect a signal including a signal related to the magnetic body amount of the object to be measured and a noise signal separately by including the first sensor unit and the second sensor unit. . Then, by comparing both signals, it is possible to separate the signal relating to the magnetic substance amount of the object to be measured and the noise signal, so that the magnetic substance amount can be measured with high accuracy.

In addition, the present invention can provide a magnetic substance analyzer having high measurement versatility without limitation in the shape and size of the object to be measured.
Moreover, the magnetic substance analyzer of the present invention can detect the amount of magnetic substance of the object to be measured with a relatively simple configuration.
In the magnetic substance analyzer of the present invention, the first sensor unit and the second sensor unit can be installed with an appropriate distance of 1 mm or more and 50 mm or less.
In the magnetic substance analyzer of the present invention, the first sensor unit and the second sensor unit can be installed with a more appropriate distance of 5 mm or more and 30 mm or less.

In addition, the magnetic substance analyzer of the present invention realizes a magnetic substance analyzer that is easy to manufacture by using a semiconductor magnetoresistive element in the magnetic field sensor section and has a relatively simple configuration and high detection accuracy. be able to.
In addition, the magnetic substance analyzing apparatus of the present invention can realize a configuration suitable for connecting the first sensor unit and the second sensor unit in a differential format and outputting the difference between the output signals of the two. it can.
Moreover, since the magnetic substance analyzer of the present invention performs a difference operation between the signal obtained from the first sensor unit and the signal obtained from the second sensor unit by the signal processing circuit, the output signal of the first sensor unit A configuration suitable for outputting a difference from the output signal of the second sensor unit can be realized.

  In the magnetic body analysis method of the present invention, the signal including the signal related to the magnetic body amount of the object to be measured and the noise signal can be separately detected by the first sensor unit and the second sensor unit. Then, by comparing both signals, it is possible to separate the signal relating to the magnetic substance amount of the object to be measured and the noise signal, so that the magnetic substance amount can be measured with high accuracy.

Embodiments of a magnetic substance analyzing apparatus and a magnetic substance analyzing method according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram for explaining an embodiment of a magnetic substance analyzing apparatus according to the present invention. The magnetic substance analyzer of the present embodiment includes a first sensor unit 1a that can detect the strength of the magnetic field, a second sensor unit 1b that can detect the strength of the magnetic field installed at a predetermined interval from the first sensor unit 1a, A magnetic material analyzer having a measured object moving means for moving a measured object (hereinafter referred to as a sample) 4 through a range in which at least one of the first sensor unit 1a and the second sensor unit 1b can detect a magnetic field. It is.

  In the configuration shown in FIG. 1, the measured object moving means is configured by the base material 3 that supports the sample 4, the fixing base 16 for fixing the base material, and the driving motor 17 that moves the fixed sample 4. According to such a configuration, the sample 4 can be moved within a range in which at least one of the first sensor unit 1a and the second sensor unit 1b can detect the magnetic field.

  Furthermore, when the sample 4 is moved, the magnetic substance analyzing apparatus of the present embodiment uses the signal obtained from the first sensor unit 1a and the signal obtained from the second sensor unit 1b to affect the amount of magnetic substance in the sample. It has magnetic substance amount detection means for detecting information. The magnetic substance amount detection means of the present embodiment is a signal processing circuit that calculates a difference using a signal obtained from the first sensor unit 1a and a signal obtained from the second sensor unit 1b. This signal processing circuit will be described later. The first sensor unit 1a and the second sensor unit 1b are electrically connected by a signal processing circuit.

  The first sensor unit 1a and the second sensor unit 1b each include a magnetic field sensor 5 whose electric characteristics change according to the magnetic field intensity, a magnetic field generator 5 that applies a static magnetic field to the sample 4, and the sample 4. I have. The magnetic field sensor 5 and the magnetic field generator 6 are fixed to the base 2 and unitized. In the illustrated configuration, the magnetic field generator 6 generates a magnetic field represented by magnetic lines of force in one direction (indicated by arrow B).

  The magnetic field sensor 5 of the present embodiment is a semiconductor magnetoresistive element, and uses a semiconductor thin film whose electrical characteristics change due to the Lorentz force generated in the magnetic field. As the semiconductor thin film, for example, a compound semiconductor such as indium antimony or a semiconductor such as silicon is used. However, the present embodiment is not limited to the configuration using the semiconductor thin film magnetic field sensor of such a member, and any member may be used as long as the electrical characteristics change due to the magnetic field. Good.

In the present embodiment, a change in electrical resistance of the magnetic field sensor 5 is detected as a change in electrical characteristics. The change in electrical resistance can be measured as a signal voltage change or current change.
The magnetic field generating unit 6 can be configured using a permanent magnet or an electromagnet configured to flow a direct current through a coil, but a permanent magnet is preferable from the viewpoint of the stability of the magnetic field strength. When a permanent magnet is used for the magnetic field generator 6, a samarium cobalt magnet or a neodymium magnet that can be applied with a strong magnetic field while being small in size is preferable. The magnetic field intensity of the magnetic field generator 6 is 500 oersted or more, preferably 1000 oersted or more, more preferably 1500 oersted or more because the semiconductor thin film of the magnetic field sensor 5 is highly sensitive under a strong magnetic field.

  FIG. 2 is a diagram for explaining the distance a of the installation position between the first sensor unit 1a and the second sensor unit 1b. The distance a is preferably 1 mm or more and 50 mm or less. Furthermore, the distance a is more preferably 5 mm or more and 30 mm or less. In addition, the distance a is represented by the distance between the surfaces of the base | substrate 2 inside each other of the 1st sensor unit 1a arrange | positioned along with the 2nd sensor unit 1b so that it may show in figure.

FIG. 3 is a view for explaining the moving direction of the sample 4 in the magnetic body analyzer of the present embodiment. In this specification, the movement of the sample 4 by the operator is also referred to as scanning.
As shown in FIG. 3A, the magnetic field sensors 5 of the first sensor unit 1a and the second sensor unit 1b detect changes in the magnetic field applied by the magnetic field generator 6 when the sample 4 moves in the direction A1. To do. The detected change in the magnetic field is output as a detection signal from the first sensor unit 1a and the second sensor unit 1b.

  As shown in FIG. 3B, the second sensor unit 1b detects a change in the magnetic field applied by the magnetic field generator 6 even when the sample 4 moves in the direction A2. In FIG. 3 (b), only the second sensor unit 1b is indicated by an arrow A2, but similarly, the first sensor unit 1a can detect a change in the magnetic field when the sample 4 moves in the direction A2. Needless to say.

That is, the sample 4 is magnetized by the magnetic field generated by the magnetic field generator 6. The magnetized sample 4 moves in the magnetic field perpendicularly across the magnetic field lines, thereby changing the magnetic flux density of the magnetic field.
The degree of magnetization of the sample 4 varies depending on the amount of magnetic material of the sample 4, and the change in the magnetic flux density of the magnetic field varies depending on the degree of magnetization of the sample 4. The resistance value of the magnetic field sensor 5 that is a semiconductor magnetoresistive element varies depending on the degree of magnetization of the sample 4. Therefore, the amount of magnetic substance of the sample 4 can be quantified by detecting the amount of change in the resistance value of the magnetic field sensor 5.

  FIG. 4 is a diagram showing a specific example of a configuration for detecting a change in the resistance value of the magnetic field sensor 5. In order to detect a change in the resistance value, as shown in FIG. 4, a resistor 41 is connected in series with the magnetic field sensor 5, one is connected to the ground 42, and the other is connected to the external voltage 43. This is possible by measuring the potential change. However, this embodiment is not limited to what detects the resistance change of the magnetic field sensor 5 by the structure shown in FIG. The resistor 41 may be a fixed resistor or a semiconductor magnetoresistive element.

  As described above, the magnetic substance analyzer of this embodiment can detect a change in a magnetic field and output a detection signal. However, at this time, hum noise generated by other devices in the environment where the magnetic substance analyzer is placed is also detected by the first sensor unit 1a and the second sensor unit 1b. As a result, the detection signals output from the first sensor unit 1a and the second sensor unit 1b include a signal indicating the amount of magnetic material of the sample 4 that should be detected and hum noise.

More specifically, the hum noise disturbs the magnetic field generated by the magnetic field generator 6 at a frequency of 50 to 60 Hz, and changes the magnetic flux density on the magnetic field sensor 5. For this reason, hum noise is detected by the first sensor unit 1a and the second sensor unit 1b.
In this embodiment, the first sensor unit 1a and the second sensor unit 1b are connected in a differential manner in order to obtain only a signal indicating the amount of magnetic material by removing hum noise from such a detection signal. And a signal processing circuit is comprised so that the detection signal obtained by the 1st sensor unit 1a and the 2nd sensor unit 1b may be outputted with a difference.

The signals output by detecting the hum noise by the first sensor unit 1a and the second sensor unit 1b have the same phase and the same intensity. For this reason, hum noise can be easily and appropriately removed by taking the difference between the output signals of the first sensor unit 1a and the second sensor unit 1b.
FIGS. 5A and 5B are diagrams for explaining the signal processing circuit of the present embodiment. FIG. 5A shows an example in which a signal processing circuit is configured as a differential amplifier 51 that performs a difference operation on detection signals that are analog signals output from the first sensor unit 1a and the second sensor unit 1b. The analog signal output from the differential amplifier 51 is output and then converted into a digital signal for use in subsequent processing.

In FIG. 5B, a signal processing circuit is configured as a differential arithmetic unit 52 that performs a difference operation after converting a detection signal that is an analog signal output from the first sensor unit 1a and the second sensor unit 1b into a digital signal. An example is shown.
In the magnetic substance analyzing apparatus of this embodiment, the detection signal to be subjected to the difference calculation may be either an analog signal or a digital signal, and either the differential amplifier 51 or the differential calculator 52 may be adopted. Good. A signal output from the differential operational amplifier 51 or the differential operational unit 52 is hereinafter also referred to as a differential signal S.

  The configuration described above operates as follows. That is, in the 1st sensor unit 1a and the 2nd sensor unit 1b, the magnetic field represented by the magnetic force line shown by the arrow B in FIG. When the magnetic substance amount of the sample 4 is detected using the first sensor unit 1a and the second sensor unit 1b, the sample 4 is scanned on the magnetic field sensor 5 included in at least one sensor unit. That is, in this embodiment, the sample 4 is scanned in the direction indicated by the arrow line A1 or the direction indicated by the arrow line A2.

  When the sample 4 is scanned in the direction of the arrow A1, depending on the position of the sample 4, for example, a change in the magnetic field is detected only in the first sensor unit 1a, and a period in which the change in the magnetic field is not detected occurs in the second sensor unit 1b. . During the period when the change of the magnetic field is not detected, only the noise signal including hum noise is detected by the second sensor unit 1b. For this reason, the signal which detected the change of the magnetic field by calculating | requiring the difference of the detection signal obtained by the 1st sensor unit 1a and the 2nd sensor unit 1b in such a period can be obtained as the difference signal S.

  When the sample 4 is scanned in the direction indicated by the arrow A2, only the magnetic field sensor 5 of the second sensor unit 1b detects a change in the magnetic field together with hum noise and the like, and the first sensor unit 1a detects only hum noise and the like. For this reason, the signal which detected the change of the magnetic field by calculating | requiring the difference of the detection signal obtained by the 1st sensor unit 1a and the 2nd sensor unit 1b similarly to having scanned the sample 4 in the direction of arrow A1. It can be obtained as a difference signal S.

  In such calculation, the shorter the distance a between the first sensor unit 1a and the second sensor unit 1b, the greater the effect of removing hum noise. However, when the distance a is shortened, the interference of the magnetic field generators 6 of the first sensor unit 1a and the second sensor unit 1b is predicted. For this reason, in the present embodiment, as described above, the appropriate range of the distance a is set to 1 mm to 50 mm, preferably 5 mm to 30 mm.

Next, an example of an experiment for measuring the amount of magnetic material performed using the magnetic material analyzer of the present embodiment described above will be described.
In the experiment, the sample 4 was scanned in the direction indicated by the arrow A2 only with respect to the second sensor unit 1b as shown in FIG. 3 (b) using the magnetic substance analyzer having the configuration shown in FIG. went. In this experiment, the difference signal S obtained by scanning the sample 4 in the direction indicated by the arrow A2 is integrated 25 times to reduce variation with respect to the value of the entire difference signal S.

Moreover, the conditions of each part of the 1st sensor unit 1a and the 2nd sensor unit 1b are described below.
Magnetic field sensor 5 Compound semiconductor made of indium antimony Magnetic field generator 6 Permanent magnet (made of samarium cobalt, magnet strength to 2000 oersted (measured on the side of the base 2 parallel to the magnetic field sensor 5)).
Distance between sensor units a Approx. 8mm

  In this experiment, as shown in FIG. 4, the magnetic field sensor 5 and the resistor 41 were connected in series, 5 V was applied as a bias voltage, and the signal was detected by monitoring the output at the midpoint p. As shown in FIG. 5A, the first sensor unit 1a and the second sensor unit 1b input the respective outputs to the differential amplifier 51 and output the differential signal S. The differential signal S is then subjected to amplification filter processing or the like. Note that processing such as amplification is a well-known technique in signal detection, and thus detailed description thereof is omitted.

  The sample used in this experiment is a magnetic particle containing ferrite (MyOne manufactured by Dynal), in which magnetic particles having different amounts are fixed to polycarbonate. The amount of magnetic material in the sample is changed by varying the amount of magnetic particles. In this experiment, five samples with large, medium, small, minute and none magnetic materials were prepared, and the magnetic material amount of each sample was measured.

Furthermore, in an experiment, in order to confirm that the magnetic substance analyzer of the present invention is not easily affected by hum noise, an environment without hum noise and hum noise are generated by turning on or off other devices placed in the experiment environment. Set the environment. The amount of magnetic material was detected under the same conditions in each environment, and the detection results were compared.
Table 1 is a table showing the results of this experiment. In this experiment, four samples with different amounts of magnetic material were measured in an environment with and without hum noise, and the results shown in Table 1 were obtained. As shown in Table 1, the magnetic substance analyzing apparatus of the present invention was able to obtain a signal that can be regarded as substantially equivalent in an environment with hum noise and an environment without hum noise. Moreover, such a result was obtained in all samples regardless of the amount of the magnetic material.

  As described above, the magnetic body analyzer of the present embodiment detects a signal including a signal related to the magnetic body amount of the sample and a noise by one of the first sensor unit 1a and the second sensor unit 1b, With the other, a noise signal can be detected. Then, only the noise signal can be separated from the detected signal by taking the difference between both signals. For this reason, it is difficult to be affected by hum noise, and the amount of magnetic substance of the sample can be measured with high accuracy.

  Moreover, the magnetic substance analyzer of this embodiment is fixed to a jig that can support the sample 4 and moves in one direction within a range in which at least one of the first sensor unit 1a and the second sensor unit 1b can detect a magnetic field. Thus, the amount of the magnetic material can be detected by changing the magnetic field. For this reason, a special jig for holding the sample is not required. Therefore, the shape and size of the sample that can be analyzed are not limited and can be used for various measurements.

The sample was magnetized by applying a static magnetic field, and the magnetic field sensor unit 5 and the magnetic field generation unit 6 that generates a magnetic field around the magnetic field sensor unit 5 were unitized. For this reason, the positional relationship between the magnetic field sensor unit 5 and the magnetic field generation unit 6 is fixed, and the magnetic field sensor unit 5 can accurately detect a change in the magnetic field caused by the movement of the sample 4.
Furthermore, since the first sensor unit 1a and the second sensor unit 1b using the magnetic field sensor unit 5 and the magnetic field generation unit 6 can be configured relatively easily, the magnetic body analyzer of the present embodiment is It can be said that the amount of magnetic substance of the object to be measured can be detected with a simple configuration.

  Further, in the present embodiment, the interval between the first sensor unit 1a and the second sensor unit 1b is set to 1 mm or more and 50 mm or less, particularly 5 mm or more and 30 mm or less. By setting such conditions, the magnetic body analyzer of this embodiment can equalize the hum noise detected between the first sensor unit 1a and the second sensor unit 1b. Furthermore, the first sensor unit 1a or the second sensor unit 1b is not affected by the magnetic field generated by the magnetic field generator 6 of the other sensor unit, and accurately detects the change in the magnetic field caused by the movement of the sample 4. be able to.

  The magnetic substance analyzing apparatus and the magnetic substance analyzing method of the present invention can detect a small amount of magnetic substance contained in a substance with high sensitivity in fields such as medical diagnosis and environmental measurement, and are also widely used in various fields. can do.

It is a figure for demonstrating the magnetic body analyzer of one Embodiment of this invention. It is a figure for demonstrating the distance of the installation position with the 1st sensor unit shown in FIG. 1, and a 2nd sensor unit. It is a figure for demonstrating the direction in which the sample is scanned in the magnetic body analyzer of one Embodiment of this invention. It is the figure which showed the specific example of the structure which detects the change of the magnetic field sensor 5 resistance value shown in FIG. It is a figure for demonstrating the signal processing circuit of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a 1st sensor unit, 1b 2nd sensor unit, 2 base | substrate, 3 base material 4 sample, 5 magnetic field sensor, 6 magnetic field generation part, 16 fixed base 17 drive motor, 41 resistor, 51 differential amplifier, 52 differential Computing unit

Claims (5)

A first sensor unit capable of detecting the strength of the magnetic field; a second sensor unit electrically connected to the first sensor unit and capable of detecting the strength of the magnetic field installed at a predetermined interval;
Said first sensor unit, at least the first object to be measured moving means for the sensor unit moves the object to be measured through the detectable range of the magnetic field change of the second sensor unit,
When the object to be measured is moved by the object to be measured moving means, a signal obtained from the first sensor unit during a period during which the object to be measured passes through a range in which only the first sensor unit can detect a magnetic field change. If, it includes a signal processing circuit for differential operation on the signal obtained from the second sensor unit, and the magnetic material amount detecting means for detecting such information on the magnetic body of the object to be measured by the signal processing circuit,
Equipped with a,
The first sensor unit and the second sensor unit include a semiconductor magnetoresistive element whose electrical characteristics change according to the magnetic field strength, and a magnetic field generation that applies a static magnetic field to the semiconductor magnetoresistive element and the object to be measured. magnetic analyzer according to claim Rukoto and means, the. 2. The magnetic substance analyzer according to claim 1, wherein a predetermined interval between the first sensor unit and the second sensor unit is 1 mm or more and 50 mm or less. . The magnetic body analyzer according to claim 2 , wherein the predetermined interval is 5 mm or more and 30 mm or less . The magnetic body analyzer according to any one of claims 1 to 3 , wherein the first sensor unit and the second sensor unit are connected in a differential manner . A first sensor unit comprising: a semiconductor magnetoresistive element whose electrical characteristics change according to the magnetic field intensity; and a magnetic field generating means for applying a static magnetic field to the semiconductor magnetoresistive element and the object to be measured; A second sensor unit comprising a resistance element and the magnetic field generation means, electrically connected to the first sensor unit, and disposed at a predetermined interval from the first sensor unit; A measuring object moving means for moving the measuring object through a range in which at least the first sensor unit of one sensor unit, the second sensor unit can detect a magnetic field change, and the first sensor. A signal processing circuit for calculating a difference between a signal obtained from the unit and a signal obtained from the second sensor unit, and the amount of magnetic material of the object to be measured by the signal processing circuit A magnetic analysis method applied to the magnetic analyzer including a magnetic detecting means for detecting such information, a
A measured object moving step of moving the measured object by the measured object moving means;
When the measured object is moved in the measured object moving step, the first sensor unit outputs a period during which the measured object passes through a range in which only the first sensor unit can detect a magnetic field change. A signal detection step of detecting a signal and a signal output by the second sensor unit;
The difference between the signal output by the first sensor unit detected in the signal detection step and the signal output by the second sensor unit is taken to detect information relating to the magnetic substance amount of the object to be measured. A magnetic substance amount detection step;
A magnetic substance analysis method comprising:

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