JPS62100671A - Magnetic field measuring system - Google Patents

Abstract

PURPOSE:To enable a highly accurate measurement of a 3-D magnetic field of an object to be measured, by measuring three components of a magnetic field separately at each measurement with one probe having a single sensor. CONSTITUTION:In a probe 16, a sensor 17 contained therein is arranged on a shift of a probe 16 by being tilted by a specified angle gamma. This probe 16 is mounted on a probe fixture 15 and the shaft of the probe 16 is adjusted with an XY stage 19 to align a rotating shaft ZM of a turntable 12. Then, a deflection yoke device 1 is fixed on a deflection yoke fixture 14. Here, X, Y and Z axes set on the device 1 are made to align various shafts of a measuring device. The Z axis is regulated with the XY stage 13 so that the sensor 17 faces a desired measuring point. Then, a magnetic field generating means is electrically energized to generate a rated magnetic field in the device 1. Under such a condition, the table 12 is turned by 90 deg. to measure an output voltage from the sensor 17 with respect to measuring angles sequentially. Then, three components of the magnetic field are computed from output voltage thus obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is suitable for use in measuring the three-dimensional magnetic field distribution of electromagnetic equipment (hereinafter referred to as an object to be measured) such as a deflection yoke device or a transformer. Magnetic field measurement method % Formula % In general, deflection yoke devices, transformers, etc. use three components of the magnetic field in the X-axis, Y-axis, and Z-axis directions ( BX,
'B,,B,) is being measured.

For this reason, in the prior art, for example, a method as shown in FIG. 13 or 14 is used to measure the magnetic field distribution of a deflection yoke device.

First, FIG. 13 shows a magnetic field measurement method using two uniaxial probes. In the figure, reference numeral 1 denotes a deflection yoke device which is an object to be measured. The deflection yoke device 1 is fixed to, for example, an X, Y stage (not shown) provided on a rotary table, and
It is movable in the axial direction. 2 is a probe that measures the magnetic fields B, , B in the X-axis and Y-axis directions among the three components of the magnetic field, and a sensor 2A consisting of a magneto-electric conversion element such as a Hall effect element is embedded in the probe 2. and is attached to a probe fixture (not shown) and suspended.

Reference numeral 3 designates a probe that similarly measures the magnetic field B2 in the X-axis direction among the three components of the magnetic field, and a sensor 3A is also embedded within the probe 3, attached to a probe fixture, and suspended.

Then, using two wooden probes 2.3, the three components B of the magnetic field are
,,By,B,, first, the probe 2 is arranged on the axis of the rotary table, and the mounting angle of the probe 2 is adjusted so that the direction of the sensor 2A coincides with the X-axis direction.

After measuring the magnetic field BX in the X-axis direction, the probe 2 is left in the same state, and the rotation/pull is rotated 90 degrees to measure the magnetic field B in the Y-axis direction. Next, probe 2 is replaced with probe 3. Then, by adjusting the mounting angle so that the orientation of the sensor 3A coincides with the X-axis direction and measuring the magnetic field B2 in the X-axis direction, it is possible to know the three-dimensional magnetic field distribution.

By the way, Bunsa 2A used for such magnetic field measurement
, 3A are usually mounted in a recessed manner. If,
The direction of sensors 2A and 3A is the X axis.

If it is mounted tilted and not aligned with the Y and Z axes,
Magnetic field components other than the measurement target are mixed into the measured value. Therefore, during measurement work, the probes 2 and 3 must be placed in a uniform magnetic field.
It is necessary to adjust the mounting angle before starting measurements. For this reason, in the conventional technique described above, each probe 2.
There was a drawback that complicated operations were required, such as the need to replace 3 and adjust the angle twice.

On the other hand, in order to eliminate the complexity of replacing probes and adjusting the installation angle as described above, a measurement method using one biaxial probe with two sensors built into one probe has been adopted. It's starting to happen.

That is, FIG. 14 shows a measurement method using one two-wheel probe. In the figure, 4 indicates the three components BX of the magnetic field.

A biaxial probe for measuring B, , B, the probe 4
A sensor 4A that measures magnetic fields B, B, in the X-axis and Y-axis directions, and a sensor 4B that measures the magnetic field B2 in the X-axis direction are embedded inside.

When such a probe 4 is used, there is no need to replace the probe mount, but the two sensors 4A and 4B
Since it is very difficult to adjust the angle so that the orientation of the two wheels coincides with the two wheels (X-Z or Y-Z) at the same time, there is a drawback that in many cases it must be accepted as a measurement error.

In addition, since it has two built-in sensors 4A and 4B,
The shape of the probe 4 inevitably becomes large, which has the disadvantage that the measurement spatial area is narrowed and the collection of detailed data in the vicinity of the coil is restricted.

[Problem that the invention seeks to solve]

The present invention was made in view of the drawbacks of the prior art described above, and provides a magnetic field measurement method that enables highly accurate three-dimensional magnetic field measurement of a measured object using one probe consisting of one sensor. The purpose is to provide

[Means for solving problems]

In order to solve the above problems, the present invention disposes one of the probe having a single sensor and the object to be measured on one axis, and the other axis (one side) parallel to the one axis. (including cases in which the axis of the probe and the object to be measured coincide with other axes), and the probe and the object to be measured are arranged around one axis among the one axis and the other axis. The structure is such that when one of the objects to be measured is rotated by 90', three components of the magnetic field of the object to be measured are separated and determined using signals output from the probe at four locations.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 12.

1 to 10 show a first embodiment of the present invention,
This example shows the rotation axis (2 and 4 axes) for rotating the deflection yoke device.
This is a case where a probe is disposed on the top, and a deflection yoke device as an object to be detected is disposed on another axis (Z-axis) parallel to the Z14 axis.

Figures 1 and 2 show the configuration of the measuring device used in this example. 1) is a rotating shaft rotated by a motor (not shown), and the rotational axis of the rotating shaft 1) is Z, the 4th axis, and It has become.

Reference numeral 12 denotes a turntable provided on the rotating shaft 1), and the turntable 12 is adapted to rotate around the 2M axis. 13 is provided on the turntable 12,
Z axis.

The XY stage is movable in the Y-axis direction, and a deflection yoke fixture 14 for fixing the deflection yoke device 1 is fixedly provided on the XY stage 13, and the Z-axis is the axis of the fixture 14. is Z. The Z axis, the \ axis, and the Y axis can be changed arbitrarily by operating the XY stage 13.

On the other hand, reference numeral 15 indicates a probe fixture, and the fixture 15 is composed of a support 15A, a movable part 15B movable in the Z-axis direction of the support 15A, and a support arm 15C provided on the movable part 15B. A cylindrical probe 16 is fixedly supported at the tip of the support arm 15C.
A sensor 17 made of an electrical conversion element is embedded. 1
8 shows a signal line for taking out a signal from the sensor 17, and one shows an XY stage to which the support column 15A is attached. In addition, in the embodiment, the XY stage 19 is not necessarily required as long as it is a fine adjustment mechanism for the probe 16.

Here, the probe 16 is adjusted to coincide with the 7.4-axis axis, and the sensor 17 has a unit normal vector n set on its magnetically sensitive portion 17A, as shown in FIG.
It is arranged obliquely so that a predetermined mounting angle γ is provided between the shaft and the 78th axis.

Note that, as described later, the angles γ-0, π/2. It is a necessary and sufficient condition for the present invention to be not π, and the angle T−π
/4 or 3π/4, the sensitivity of the sensor 17 becomes equal to the three components of the magnetic field.

Next, the principle of magnetic field measurement of the deflection yoke device using the measuring device configured as described above will be explained in FIGS. 4 to 10.
An example of measurement using a rectangular coordinate system and a cylindrical coordinate system will be described with reference to the drawings.

Note that measuring the magnetic field of the deflection yoke device means separating and extracting three components set in the deflection yoke device at each measurement point in the \coordinate axis direction.

Here, if the position of the sensor 17A in the probe 16 with respect to the X, Y, and Z axes in FIGS. Since the rectangular coordinate system...P (x, y, z) and the cylindrical coordinate system...P (r, θ, z) are given, the three components of the magnetic field at the measurement point P are rectangular coordinate system...( B,,B,,B,) Cylindrical coordinate system - (
B, , B e, B7. ) can be given as

First, as the first three-component magnetic field separation method, three components of the magnetic field (B, , By) are calculated using a rectangular coordinate system.

The case of measuring B,) will be described.

First, as shown in FIG. 6, the magnetic sensing part 17A of the sensor 17
The origin 0 is set at the center P of the local coordinate system X.

Set Y and Z. Here, the magnetic sensing part 17 of sen'+17
A unit normal vector n- erected perpendicular to A has the angle between the position normal vector n and the local coordinate system X, Y, and Z axes α,
Letting β and γ be the following (1) generation.

n = COS α 1 ”CO5β j 4-co
s r k=5in γ' cos δ i
j-sin γ' Sin δ j+cos
r k ... (1) However, as shown in FIG. 6, the projection vector r) of the vector I-n from the angle δ and X1iii to the Z plane.8. The angle is up to.

In addition, the magnetic field (E'i1
If the flux density) is B, then B=BX i →-13yj+I3□k...(2
), the output voltage (measured value) of the sensor 17 is given by the following equation (3).

VH=k (B −n) =k (BX′sin γ−cos δ+B,
9sin γ・sin δ+B, ・cos
T ) - (3) where k is the calibration constant of the instrument.As is clear from equation (3) above, the values that characterize the inclination of the sensor 17 are the two angles T and δ, and the unit normal vector n is x , if the direction does not match any of the y and z axes, the output voltage ■. is BX.

It contains three components: B, ,B. Therefore, no matter what correction coefficient is applied to the output voltage V++, B, ,B,
, B, cannot be separated into their respective components. Note that when the unit normal vector n coincides with the coordinate axis direction, the magnetic field B
Of course, only one of the three components can be measured individually.

Therefore, if the sensor 17 has a slope, the output voltage Vll
A method for separating three components of the magnetic field, BX, B, , B, will be described below.

First, in FIG. 6, without moving the center P of the sensor 17, the probe 16 is rotated 90 degrees with the z-axis as the central axis.
This is achieved by positioning the deflection yoke device 1 and rotating the turntable 12 clockwise by 90 degrees without considering how the output voltage V1) will be obtained when rotating counterclockwise by 90 degrees. I can do it.

Here, the rotation of the sensor 17 is m-position normal hector n
is the rotation around the z-axis of . Therefore, since the Z component n2 of the unit normal vector n does not change and remains constant, the result is a rotation around the origin O of the projection vector nXy projected onto the Z plane (see FIG. 7).

Therefore, if the first rotational position of the projection vector n, xy is the first quadrant, then the second... Third. The fourth elephant is required. That is, it is determined as follows.

Similarly, It is required as.

Therefore, when the sensor 17 is rotated counterclockwise by 90", the output voltage of the sensor 17 is
H3+ vH4 is Vo =k (I3-173.
), it becomes as follows.

■ When rotation angle is 0: V)++=k (Bx 1sin γ' CO5δ+
B, −5in r ・sin δ×B2 ・cos
γ) ■ When the rotation angle is π/2: Vnz=k (BX ・sin r ・sin δ+
13. −5in γ' cos δ+BZ ′c
os r) ■ When the rotation angle is π: Voz= k (-BX rumor sin γ' cos δB
y Sin γ・sin δ+B z ・cos
r ) ■ When the rotation angle is 3/2π: VH4=k (BX -5in r -5in δ-
B, -5in T °eos δ+Bz'CO3γ
) where the output voltages VHI and VH3, or vHz and V
When calculating the average value of the sum of H4, only the B component is calculated as follows (4
)2 can be extracted separately.

Further, when the average value of the differences between the output voltages VHI and VH3 and between VH2 and VH4 is calculated and rearranged, the following equation is obtained.

Bx'CO5δ10B, -5in δBx Sjn
δ+By CO5δ Therefore, BX and By can be determined separately from equations (5) and (6). That is, from the calculation of (5) 2x cos δ - (6) 2X5in δ, BX can be determined by the following formula.

Similarly, By can be obtained from the following equation by calculating the equation (5) X5in δ+(6) x cos δ.

As mentioned above, if the inclination angles T and δ of the sensor 17 are actually measured in advance, the three components BX, By, and B of the magnetic field can be obtained.

is the actual measured value of the output voltage V HI I V s z +
vs z , V 1) 4 to equation (7), respectively. (
They can be separated and extracted based on equations 8) and 4. At this time, the inclination angles T and δ can be easily measured using Helmholtz coils.

Note that among the inclination angles γ and δ, equation (4), equation (7),
The inclination angle γ giving the denominator of equation (8) is O1π/2. It is a necessary and sufficient condition that it is not π. Also, γ-45°.

When the angle is 135°, the sensor 17
have the same sensitivity. Furthermore, if n=0.1.2°,
Each of the above formulas becomes a simpler formula.

Thus, in order to determine the three components BX, B, , B of the magnetic field using the measuring apparatus shown in FIGS. 1 and 2, the following measurement order is used.

First, the probe 16 has a built-in sensor 17 inclined at a predetermined angle γ with respect to the axis of the probe 16 (corresponding to the 2M axis), and a Helmholtz coil or the like is used to tilt the predetermined angle γ. Use the known ones. Then, such a probe 16 is attached to the probe fixture 15, and the axis of the probe 16 is adjusted by the XY stage 19 so that it coincides with the rotation axis ZM of the turntable 12. Note that this procedure can be simplified if the probe 16 has a positioning part that regulates the mounting angle. In any case, the angle γ.

δ is a constant that only needs to be calibrated once as a measuring device. On the other hand, the angle δ, which is the mounting angle of the probe 16, is determined by a Helmholck coil or the like J1). Further, the probe 16 is adjusted to a predetermined height position on the rotation axis 2.4.

Next, the deflection yoke device 1 is fixed to the deflection yoke fixture 144. At that time, the x, y,
The z-axis is made to coincide with each axis direction of the measuring device. Next, the z-axis is adjusted by the XY stage 13 so that the sensor 17 faces the desired measurement point.

Next, the magnetic field generating means (not shown) is energized to generate a rated magnetic field in the deflection yoke device 1.

In this state, rotate the turntable 12 by 90°,
Output voltage V□~V from sensor 17 for each measurement angle
Measure □ sequentially.

Calculate B2.

In this way, the three components of the magnetic field at a certain desired measurement point were measured and calculated. However, in order to measure the three components of the magnetic field at other measurement points, the X and Y stages 13 are used to measure and calculate the three components of the magnetic field. 1 to set a new l-axis.

Further, the Z-direction position of the sensor 17 is newly set by sliding the probe fixture 15 in the Z-direction. Then, as described above, the turntable 12 is rotated by 90 degrees, and the output voltages V□ to ■8, 4 from the sensor 17 at the newly set measurement points are sequentially measured and calculated.

In this way, the three-dimensional magnetic field distribution of the entire deflection yoke device 1 can be measured. Moreover, the output voltages ■□ to VII4 are measured values, and the inclination angle T5 δ of the sensor 17 is a known value, so the measurement results are not subject to error factors due to the inclination of the sensor, as in the prior art. No need to consider.

The above describes the three components of the magnetic field (BX) using the rectangular coordinate system.

By, B-), but then the second
A case will be described in which the three components of the magnetic field (Br, Bo, B, I) are obtained using a cylindrical coordinate system as a method for separating the three components of the magnetic field.

First, as shown in FIGS. 8 and 9, the deflection yoke device 1
From the Zl and l axes of the coordinate system, the direction of the center line with radius r is radial from the Zl4 axis, and is uniquely determined as the fundamental vector e1. Further, the direction of the fundamental vector e θ is taken in the direction of the rotation angle θ as defined. Note that the basic vector e2
The direction of does not change.

Here, let γ be the angle between the fundamental vector ez and the unit normal vector n, see Figure 8), n, -cos r
becomes. Also, if the number of projection vectors obtained by projecting the unit normal vector n onto the Z plane is n, then the size is sin
Since T, n, = sin r・cos φ, n
o = sin y -5in φ. Note that the angle φ is the angle from the base line of the local coordinate system (direction of the fundamental vector er) to the projection vector nX. Therefore, in the cylindrical coordinate system, the unit normal vector n is given by the following equation (9).

rz = sin r cos φ e.

+sin r 0sin φ e 6 +cos r
e, -・(91) On the other hand, the magnetic flux density B at the origin 0 is: B = B, e r + B oe 6 + B2 e ,
-00), the output voltage V□ of the sensor 17 is given by the following equation.

■□−k (B −rr ) = k (B r・sin T ・cos φ1B e ・sin T sin φ+B, −cosr
)...(1)) Comparing equation (1)) with equation (3) above, it can be seen that there is a correspondence relationship between the cylindrical coordinate system and the rectangular coordinate system. Therefore, the three components of the magnetic field B, , Bo, and B are the above-mentioned equations (7) and (8).

It can be easily obtained by replacing equation (4) with equation (12). That is, each component B, , Bo, B is as shown in the following equation.

...(15) Each component Br of the magnetic field when using a cylindrical coordinate system.

Bo, B, can be found using equations (13) to (15) above, but the measurement method using the measuring device shown in Figures 1 and 2 is similar to the case using the rectangular coordinate system. What is necessary is to measure the output voltage v, 41 to V) 14 of the sensor 17 obtained when the yoke device 1 is rotated by 90 degrees.

Here, when a cylindrical coordinate system is used, the Z-axis of the deflection device 1 is always on the X, 4-axis, or YM wheel axis of the measuring device. Therefore, the difference in the position of the turntable 12 during measurement between the rectangular coordinate system and the cylindrical coordinate system is always the angle θC-a
rc tan ).

Note that the coordinate transformation between the rectangular coordinate system and the cylindrical coordinate system is
As is clear from FIG. 10, the coordinate transformation formula shown in equation (16) below may be used, and which coordinate system to use can be freely selected for measurement and analysis.

Next, Figure 1) shows a second embodiment of the present invention, and the feature of this embodiment is that the deflection yoke device as the object to be detected is arranged on the rotation axis (2° axis) for the deflection yoke device. However, this is a case where the probe is arranged on another axis (Z axis) parallel to the Z9 axis.

That is, in Figure 1), the same components as those of the measuring device used in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.In this embodiment, the rotating shaft 21 having the axis Z1 is rotated. A table 22 is provided, and a center axis is Z on the turntable 22, and a deflection yoke fixture 24 is vertically aligned with the axis.
This is due to the fact that it is fixed. Note that in the case of this embodiment, the XY stage 13 used in the first embodiment is not necessarily necessary, and is therefore omitted.

Although the present embodiment is constructed as described above, there is no substantial difference in the measurement method using this measuring device from that of the first embodiment. That is, turntable 22
When the deflection yoke device 1 is rotated by 90", the output voltages V□ to ■□4 obtained from the sensor 17 are measured. Then, each component of the magnetic field BX when using a rectangular coordinate system
, By, B is the formula (7).

When calculated using formulas (8) and (4)2, and using a cylindrical coordinate system, each component of the magnetic field B, , Bθ, B2 is (13)
It is calculated using the following formulas: Equation (14) and Equation (15).

Next, FIG. 12 shows the embodiment of the present invention shown in FIG. This is a case in which a deflection yoke device is disposed, and a probe is rotatably disposed on another axis (Z axis) parallel to the 2.4 axis.

That is, in FIG. 12, the same components as those of the measuring device used in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted. The rotation axis of this rotation shaft 21 is a Z line. 32 is another turntable provided on the rotating shaft 31, 33 is another XY stage provided on the turntable 32, and on the XY stage 33 is a probe fixture 34 for fixing the probe 16. is fixed, and the probe 16 is attached to the fixture 34. Then, the axis of the probe 16 is adjusted by the XY stage 33 so that it is aligned with the Z axis.

Here, the deflection yoke device IX is fixed to a deflection yoke fixture 14 on the XY stage 13. Therefore, the axis of the deflection yoke device 1 is aligned with the axis (ZS axis) of the deflection yoke fixture 4. Further, the probe 16 is arranged so that the axis of the probe 16 is on the Z axis, which is parallel to the Zo axis. Note that the 2M axis in this embodiment does not mean the rotational axis of the rotating shaft 1), but the axis of the deflection yoke fixture 14, that is, the axis of the deflection yoke device 1, and therefore the Zr2 axis is variably raised by the XY stage 13, and measurement points are set.

The measuring device used in this example is configured as described above,
2. In the case where the deflection yoke device 1 is arranged on the 4-axis and the probe 16 is arranged on the Z-axis, ζ is also obtained. A total of 1γ substitutions in the rectangular coordinate system according to the first embodiment, Equations (7), Equations (8), (
4) or calculation formula (13) using a cylindrical coordinate system.

Equations (14) and (15) can be applied as they are.

Next, the measurement order according to this embodiment will be described.

First, the probe 16 is attached to the probe fixture 34, and the axis of the probe 16 is adjusted to match the rotation axis Z of the turntable 32.

Next, the deflection yoke device 1 is fixed to the deflection yoke fixture 14, and the Z-axis is adjusted by the XY stage 13 so that the sensor 17 faces a desired measurement point.

In this state, the magnetic field generating means is energized, the other turntables 32 are rotated by 90 degrees, and the output voltages VHI to ■□ from the sensor 17 at a certain measurement point are sequentially measured. Note that when measuring other measurement points, the deflection yoke device 1 may be moved to a desired position using the XY stage 13.

Note that in the case of this embodiment, the rotating shaft 1) and the turntable 12 are not necessarily required, and only the XY stage 13 may be used.

In each of the embodiments of the present invention, the deflection yoke device 1 is used as an example of the object to be detected, but it can be used to measure the three-dimensional magnetic field distribution of various electromagnetic devices such as transformers and solenoid coils. Further, the probe 16 is not limited to a cylindrical shape, but can have any shape. Furthermore, the method for separating the three components of the magnetic field is not limited to the rectangular coordinate system or the cylindrical coordinate system, but it goes without saying that a polar coordinate system may also be used. Furthermore, although two parallel axes, the Z8 axis and the Z axis, are illustrated as being spaced apart from each other, the Z.

The axis and the Z-axis may be made to coincide with each other; in short, they may be separated from each other or made to coincide with each other depending on the shape of the object to be detected.

〔Effect of the invention〕

The magnetic field measurement method according to the present invention is as described in detail above, and uses one probe having a single sensor.
Since the structure is configured so that three components of the magnetic field can be separated and measured for each measurement, it is possible to eliminate error factors caused by the tilt of the sensor inside the probe, allowing highly accurate measurements, and also reducing the size of the probe. This makes it suitable for magnetic field measurements of deflection yoke devices with limited measurement space, and furthermore, since there is no need to replace the probe once it is set, measurements can be automated.

[Brief explanation of drawings]

1 to 10 relate to the first embodiment of the present invention,
Fig. 1 is a front view of the measuring device, Fig. 2 is a plan view in the direction indicated by the nn arrow in Fig. 1, Fig. 3 is a perspective view showing the mounting angle of the sensor with respect to the probe, and Fig. 4 is a rectangular coordinate system. An explanatory diagram showing the relationship between the cylindrical coordinate system, FIG. 5 is a plan view of FIG. , Fig. 7 is an explanatory diagram showing a magnetic field separation method using a rectangular coordinate system, Fig. 8 is an explanatory diagram showing the relationship between the fundamental vector and the unit normal hector when measuring three components of a magnetic field using a cylindrical coordinate system, Figure 9 is an explanatory diagram showing the relationship between the overall coordinates and local coordinates when three components of a magnetic field are measured using the same cylindrical coordinate system, and Figure 10 is an explanatory diagram showing the relationship between the overall coordinates and local coordinates when three components of a magnetic field are measured using the cylindrical coordinate system. Explanatory drawings, Figure 1) is a front view of the measuring device used in the second embodiment of the present invention, Figure 12 is a front view of the measuring device used in the third embodiment of the present invention, Figures 13 and 14 The figure relates to the conventional technology,
FIG. 13 is an explanatory diagram showing a magnetic field measuring method using two uniaxial probes, and FIG. 14 is an explanatory diagram showing a magnetic field measuring method using one biaxial probe. 2... Deflection yoke device (object to be measured), 1), 21°3
1...Rotating axis, 12,22.32...Turntable, 13.19.33...xy stage, 16...
Probe, 17...sensor. Y Figure 12 Now Figure 13 Figure 14

Claims (4)

[Claims] (1) A probe with a single sensor and one of the object to be measured are arranged on one axis, and another axis parallel to the one axis (one axis and the other axis coincide) The other of the probe and the object to be measured is disposed on the object (including cases where the object is measured), and one of the probe and the object to be measured is centered around one of the one axis and the other axis A magnetic field measurement method in which three components of the magnetic field of the object to be measured are separated and determined using signals output from four locations from the probe when rotated by 90 degrees. (2) The magnetic field measuring method according to claim (1), wherein the three components of the magnetic field are determined separately using a rectangular coordinate system. (3) The magnetic field measurement method according to claim (1), wherein the three components of the magnetic field are determined separately using a cylindrical coordinate system. (4) The probe according to claim (1), wherein the sensor is arranged at a predetermined angle (excluding 0, π/2, and π) with respect to the axis of the probe. Magnetic field measurement method.