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WO1991013366A1 - Procede et appareil de detection magnetique - Google Patents

Procede et appareil de detection magnetique Download PDF

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Publication number
WO1991013366A1
WO1991013366A1 PCT/JP1991/000250 JP9100250W WO9113366A1 WO 1991013366 A1 WO1991013366 A1 WO 1991013366A1 JP 9100250 W JP9100250 W JP 9100250W WO 9113366 A1 WO9113366 A1 WO 9113366A1
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WO
WIPO (PCT)
Prior art keywords
detection
magnetic field
magnetic sensor
signal
waveform
Prior art date
Application number
PCT/JP1991/000250
Other languages
English (en)
Japanese (ja)
Inventor
Corporation Nkk
Seigo Ando
Original Assignee
Nippon Kokan Kk
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP11528490A external-priority patent/JPH03272483A/ja
Priority claimed from JP2278918A external-priority patent/JP2617615B2/ja
Application filed by Nippon Kokan Kk filed Critical Nippon Kokan Kk
Publication of WO1991013366A1 publication Critical patent/WO1991013366A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/04—Measuring direction or magnitude of magnetic fields or magnetic flux using the flux-gate principle

Definitions

  • the present invention relates to a magnetic detection device and a magnetic detection method using a saturable magnetic sensor.
  • a magnetic leak detection device is used as one of the defect detection devices for detecting defects existing inside or on the surface of a steel sheet.
  • a magnetic leakage device it is necessary to accurately detect the leakage magnetic flux.
  • a magnetic detection device using a saturable magnetic sensor has been proposed as a magnetic detection device for detecting magnetism with high accuracy (Japanese Patent Application Laid-Open No. Hei 13-89082).
  • FIG. 4 is a block diagram showing a schematic configuration of a magnetic detection device using the saturable magnetic sensor.
  • reference numeral 1 denotes a rectangular wave generating circuit that outputs a high-frequency rectangular wave signal.
  • the rectangular wave signal output from the rectangular wave generating circuit 1 is supplied to the following differentiating circuit 2 so that the rising and falling times of the rectangular wave are obtained. Is converted into a pulse signal having a trigger waveform shape synchronized with the timing. Then, the pulse signal of the trigger waveform output from the differentiating circuit 2 is applied as a high-frequency excitation signal to the magnetic sensor 4 via the impedance element 3 composed of a resistor.
  • the magnetic sensor 4 is configured by winding a detection coil 6 around a core 5 of a ferromagnetic material formed in, for example, a rod shape.
  • the high-frequency excitation signal e is applied to one end of the detection coil 6 of the magnetic sensor 4 via the impedance element 3, and the other end is grounded.
  • the terminal voltage of the detection coil 6 is the detection signal e of the magnetic sensor 4.
  • the output voltage V corresponding to the intensity of the magnetic field detected by the magnetic detection device from the voltage detection circuit 7. Is obtained.
  • the voltage of the high-frequency square wave signal output from the square wave generation circuit 1 is controlled to increase the current of the high-frequency excitation signal flowing through the detection coil 6 and magnetize the core 5 to the saturable region. I do. Therefore, in this state, the detection signal e indicated by the terminal voltage of the detection coil 5.
  • Figure 5 shows the amplitude of the waveform So that it becomes constant.
  • the magnetic detection device configured as shown in FIG. 4 still has the following problems.
  • the detection coil 5 wound around the core 5 formed of the ferromagnetic material of the magnetic sensor 4 to magnetize the core 5 to the saturable region.
  • High-frequency excitation applied to the magnetic sensor 4 via the impedance element 3 in order to accurately detect the positive and negative peak values Va and 1 Vb in the detection signal e Q taken out of the magnetic sensor 4
  • the signal ei is a trigger waveform pulse signal. Therefore, the current flowing through the detection coil 5 becomes a high-frequency current due to the trigger waveform. Therefore, in order to magnetize the core 5 to a saturable region with the trigger waveform pulse signal, the voltage of the high-frequency excitation signal ei needs to be significantly increased.
  • the square wave generating circuit 1 also needs to output a square wave signal having a peak value of 15 to 25 V P — P.
  • the detection signal e. Output voltage V corresponding to the external magnetic field applied from the waveform of In the voltage detection circuit 7 for calculating the peak value, a detection circuit for detecting each of the positive and negative peak values Va and one Vb, an addition circuit for adding the obtained peak values Va, — Vb, and the like are incorporated. This complicates the circuit configuration.
  • a high-voltage DC power supply, a detection circuit, an addition circuit, and the like are required, not only does the circuit configuration of the entire magnetic detection device become complicated, but also the overall device becomes large.
  • the present invention has been made in view of such circumstances, and an object of the present invention is to obtain a detection signal by applying an AC exciting current having a predetermined effective value to a detection coil of the magnetic sensor.
  • the external magnetic field strength can be easily detected from the degree of change in the width of the signal waveform in the detection signal, thereby simplifying the circuit configuration of the entire device, It is an object of the present invention to provide a magnetic detection device and a magnetic detection method capable of reducing the size of the entire device and reducing the manufacturing cost.
  • a magnetic detection device includes a saturable magnetic sensor having a detection coil wound around a core formed of a magnetic material, and a detection coil of the magnetic sensor.
  • an excitation signal generating circuit for applying an AC excitation current having a predetermined effective value through an impedance element to magnetize the core to a saturation region, and a detection signal waveform extracted from both ends of the detection coil at a predetermined threshold.
  • a comparator for normalizing with a value, and a counter for measuring the pulse width of the normalized signal output from the comparator.
  • the magnetic detection device of the second invention is provided with a low-pass filter for detecting the pulse width of the normalized signal output from the comparator as an average DC component, instead of the counter.
  • a magnetic sensor formed by winding a detection coil around a core made of a ferromagnetic material is brought close to a magnetic field to be measured, and the detection coil of the magnetic sensor is connected to the detection coil via an impedance element.
  • a pulse voltage is supplied, positive and negative peak values of a voltage generated at both ends of the coil are detected, and the detected positive and negative peak values are added.
  • the added value is compared with a measured value corresponding to the measured magnetic field. It is characterized by doing.
  • an AC excitation current having a predetermined effective value is applied to the detection coil of the magnetic sensor from the excitation signal wave generation circuit. Therefore, the effective current value of the AC exciting current is larger than the pulse signal of the trigger waveform. Therefore, the voltage of the AC exciting current required to magnetize the core of the magnetic sensor to the saturable region can be set low.
  • the core is magnetized in the positive and negative directions by the AC voltage applied to the detection coil, but saturates when the current exceeds a certain current value.
  • the waveform of the detection signal extracted from both ends of the signal has a predetermined width.
  • the detection coil crosses the magnetic field excited by the AC excitation current.
  • the external magnetic field is applied, the external magnetic field is added to or subtracted from the magnetic field of the AC exciting current, so that a part of the waveform of the detection signal is deformed.
  • the deformed detection signal waveform is normalized by a predetermined threshold value in a comparator. Then, the degree of deformation of the detection signal waveform is detected by the pulse width of the normalized signal. Therefore, the external magnetic field strength is detected from the change in the pulse width.
  • the pulse width is directly measured at the counter, and according to the second magnetic detection device of the present invention, the pulse width is normally measured by the low-pass filter.
  • the pulse width is measured by detecting the average DC component of the digitized signal.
  • a positive or negative pulse voltage is supplied from the pulse voltage supply source to the coil of the magnetic sensor that is close to the magnetic field to be measured, whereby the positive or negative voltage of the voltage generated between both ends of the coil is supplied.
  • a peak value is detected by a pair of peak value detection means, and the change of the magnetic field to be measured (external magnetic field) detected by the magnetic sensor is measured as a change of a voltage level by adding each peak value by an adder. Can be.
  • a detection signal is obtained by applying an AC exciting current having a predetermined effective value to the detection coil of the magnetic sensor, and a part of the waveform of the obtained detection signal is an external magnetic field. Is detected. Therefore, the voltage value of the AC excitation signal applied to the magnetic sensor can be significantly reduced, and the external magnetic field strength can be easily detected from the degree of deformation of the signal waveform of the detection signal. As a result, each circuit configuration can be simplified, and the entire detection device can be reduced in size and manufacturing cost can be reduced ⁇ Further, according to the magnetic detection method of the present invention, detection sensitivity to a minute magnetic field can be improved, and power can be saved by driving the coil of the magnetic sensor with a pulse voltage. Therefore, for example, it is very effective in realizing the magnetic measurement method of the present invention by battery operation.
  • FIG. 1 is a block diagram showing a schematic configuration of the magnetic detection device of the embodiment.
  • reference numeral 11 denotes an excitation signal generation circuit which outputs, for example, a high-frequency excitation signal having a triangular waveform as an AC excitation signal having a predetermined effective value.
  • the excitation signal wave generation circuit 11 includes a high-frequency oscillator 1 2 and a frequency divider 13 and a triangular wave generation circuit 14.
  • the high-frequency oscillator 12 outputs a clock signal d having a high frequency, for example, 10 MHz. This clock signal d is divided into, for example, 1 by the next frequency divider 13 and then input to the triangular wave generation circuit 14.
  • This triangular wave generation circuit 14 converts a high frequency excitation signal a as an AC excitation signal having a triangular wave shape with a period T 0 as shown in FIG. 3 through an impedance element 15 composed of a resistor, for example, through a magnetic sensor 1. Send to 6.
  • the magnetic sensor 16 is configured by winding a detection coil 18 around a ferromagnetic core 17 formed in, for example, a rod shape.
  • the high frequency excitation signal a via the impedance element 15 is applied to one end of the detection coil 18 of the magnetic sensor 16, and the other end is grounded.
  • the terminal voltage of the detection coil 18 is extracted as a detection signal b of the magnetic sensor 16 and input to the (+) side input terminal of the comparator 19 as a waveform shaping circuit.
  • the (1) side input terminal of this comparator 19 is grounded.
  • Comparator 19 outputs a normalized signal c having a H (high) level when the detection signal b is higher than the ground potential (0 V) and an L (low) level when the detection signal b is lower than the ground potential (0 V). Output.
  • the voltage level of the normalized signal c is a constant level signal of 5 V at H level and 0 V at L level.
  • the normalized signal c having a constant level output from the comparator 19 is input to the control terminal G of the counter 20 and to the low-pass filter 21.
  • the clock signal d output from the high-frequency oscillator 12 is input to the clock terminal CP of the counter 20.
  • the counter 20 is activated before being applied to the control terminal G.
  • the counting operation of the number of clocks of the clock signal d is started, and the normalized signal c is changed from the H level to the L level.
  • the count operation ends in synchronization with the falling timing. That is, the counter 20 measures the pulse width T indicated by the H level period of the normalized signal c.
  • the digital pulse width T measured by the counter 20 is sent to an arithmetic circuit 22 composed of, for example, a microcomputer or the like.
  • the low-pass filter 21 has a relatively large time constant, and cuts off the high-frequency components among the frequency components included in the pulse-like waveform of the normalized signal c, and removes only the low-frequency components. Let it pass. Therefore, this low-pass filter 21 outputs an average DC voltage proportional to the effective average voltage of the normalized signal c. Since the average DC voltage of the normalized signal c corresponds to the pulse width T of the normalized signal c, as a result, the voltage of the analog output signal f of the low-pass filter 21 becomes equal to the pulse of the normalized signal c. Corresponds to the width. Then, the output ftf having a voltage value corresponding to the pulse width T is input to the analog arithmetic circuit 23.
  • an excitation signal generating circuit 11 As shown in FIG. 6, an excitation signal generating circuit 11, an impedance element 15, and a detection coil 18 wound around the outer periphery of a ferromagnetic core 17 are connected in series.
  • the magnet 25 is for applying an external magnetic field to the magnetic sensor 16 including the core 17 and the detection coil 18.
  • the excitation signal generation circuit 11 generates an AC power supply voltage waveform (high-frequency excitation signal) as shown in Fig. 7A.
  • the resistance value R is constant
  • the detection signal b is changed in accordance with the I impedance Z s of the detection coil 1 8.
  • the impedance Z s of the detection coil 1 8 which is ⁇ core 1 7 of the ferromagnetic material is proportional to the permeability of the core 1 7.
  • the voltage waveform of FIG. 7A is entirely shifted by the DC component to the positive side as shown in FIG. 7B due to the effect of the external magnetic field.
  • the voltage waveform in FIG. 7A is shifted to the negative side by the external magnetic field by only the DC component. If the external magnetic field is an alternating magnetic field, the shifts in Figs. 7A and 7B are repeated. Therefore, the output voltage generated across the detection coil 18 has a waveform as shown in FIG. 7D. Then, the waveform of the external magnetic field by the magnet 2 5 with pressurized Erare absence positive, a negative symmetrical waveform, the voltage V 2 in the positive direction of voltage V and the negative direction are equal.
  • the external magnetic field can be indirectly measured by comparing the positive voltage V i and the negative voltage v 2 of the output voltage generated at both ends of the detection coil 18 and obtaining the difference. Therefore, if this principle is applied to the magnetic flux leakage detection method, the external magnetic field is generated by the defect, so that the defect can be detected after all.
  • the impedance Z s is also the excitation current value of the detection coil 1 8, i.e., which changes depending on the value of the high frequency excitation signal a applied to the detection coil 1 8. Therefore, the impedance Z s changes rapidly in the process of increasing the high-frequency excitation signal a shown in FIG. 3, and the detection signal b rapidly rises or falls. Therefore, as shown in FIG.
  • the waveform of the detection signal b is a substantially rectangular waveform extending from 0 V to the positive side and the negative side.
  • the pulse width 1 of this substantially rectangular waveform is the period T of the high-frequency excitation signal a. 1 of 2. That is, the input triangular waveform becomes a substantially rectangular waveform.
  • the threshold value of the comparison circuit 19 is 0 V, so the normalized signal c output from the comparison circuit 19 Has the same pulse width as the pulse width of the detection signal b.
  • the width of the pulse is measured by the counter 20 and sent to the arithmetic circuit 22.
  • the arithmetic circuit 22 has a period T of the known high-frequency excitation signal a. Compared with the detected pulse width and T. In the case of, it is determined that there is no external magnetic field.
  • an output signal f having a DC voltage is input from the low-pass filter 21 to the arithmetic circuit 23. Then, the arithmetic circuit 23 determines from the DC voltage V that no external magnetic field is applied.
  • it changes from even a pulse width T which is input from the counter 20 to the arithmetic circuit 22 to T 2 or T 3.
  • the output signal is the external magnetic field Eta input 2 or pulse width T 2 or T 3 corresponding to an Eta 3 by mouth one pass filter 21 to the arithmetic circuit 23 of the normalized signal c output from the comparator 19 f detected by the DC voltage V 2 or V 3. Therefore, also in the arithmetic circuit 23 of this ⁇ analog, with at comparison with the DC voltage in a state where the external magnetic field is not applied, the applied external magnetic field H 2 or - c the amount of H 3 is thus calculated, The magnitude and direction of the magnetic field externally applied to the magnetic detection device are calculated digitally or analogly by the arithmetic circuits 22, 23.
  • the signal waveform of the high-frequency excitation signal a as the AC excitation current applied to the magnetic sensor 16 has a predetermined effective value as shown in FIG. It has a triangular shape. Since the effective current value of the high-frequency excitation signal a is larger than the trigger signal pulse signal e in the conventional detector shown in FIG. 4, the high-frequency necessary for magnetizing the core 17 of the magnetic sensor 16 to saturable is obtained.
  • the voltage of the excitation signal a can be set low. In the example device, the voltage value of the high-frequency excitation signal a could be reduced to 5 VP-P.
  • the DC power supply for driving the high-frequency oscillator 12, the frequency divider 13, and the triangular wave generation circuit 14 of the excitation signal generation circuit 11 is normally at a constant level of 5 V, which is sufficient. That is, a DC power supply of 15 to 25 V is not required unlike the conventional device. As a result, the circuit configuration of the entire device can be simplified.
  • a circuit for detecting the intensity of the external magnetic field from the detection signal b of the magnetic sensor 16 includes, for example, a waveform shaping circuit composed of a comparator 19 having a simple circuit configuration, a counter 20 and a low-pass filter 21. It can be realized with a low-cost and simple circuit member. Accordingly, the circuit configuration of the excitation signal generation circuit 11 and the signal processing circuits 19, 20 and 21 for the detection signal can be simplified, so that the entire magnetic detection device can be made compact, lightweight and inexpensive. .
  • each of the above-described circuits can be configured by a TTL circuit, IC can be achieved, and the entire device can be further reduced in size.
  • the output signal of the counter 20 is a digital signal of a fixed level, it is hardly affected by external noise. In addition, inspection and repair are easy because of the simple configuration. Therefore, sufficient measurement accuracy can be obtained even under adverse environmental conditions such as a factory production line.
  • the comparator 19 when used as a waveform shaping circuit as in the embodiment, it can be diverted to, for example, a proximity switch or the like only by changing the threshold value.
  • conventional magnetic detectors using a simple pickup coil utilizing the electromagnetic induction effect, etc. could measure only a time-varying magnetic field due to the measurement principle, but a saturable magnetic sensor By using 16, it is possible to accurately measure a magnetic field over a wide frequency range from a DC magnetic field to a high-frequency magnetic field.
  • the degree of deformation (pulse width change) at which a part of the waveform of the detection signal b of the magnetic sensor 16 is deformed due to the external magnetic field is measured, and the external magnetic field strength is determined from the degree of deformation. Has been detected. Therefore, the waveform itself depends on the external environment such as temperature. Since it is hardly affected by the conditions, it is not necessary to take a temperature compensation measure especially for the detection signal b of the magnetic sensor 16.
  • the present invention is not limited to the embodiments described above.
  • the case where the DC external magnetic field + H 2 , —H 3 is measured has been described, but it is needless to say that the AC external magnetic field can also be measured as described above.
  • a high-frequency excitation signal a having a triangular wave shape was used as an AC excitation current applied from the excitation signal generation circuit 11 to the detection coil 18 of the magnetic sensor 16 via the impedance element 15, as in the embodiment.
  • external magnetic field + H 2 DC if you measure an H 3 can be used exciting current of a low frequency to obtain a sufficiently high measurement accuracy. That is, the frequency of the AC excitation current applied to the magnetic sensor 16 is desirably about 10 times or more the frequency of the external magnetic field to be measured, but this condition is not necessarily satisfied depending on the magnetic field to be measured. Even without it, it is possible to obtain sufficiently high measurement accuracy.
  • the waveform of the AC exciting current applied to the detection coil 18 of the magnetic sensor 16 is a triangular wave shape. There may be.
  • FIG. 8 is a block diagram for implementing the magnetic detection method of the present invention.
  • reference numeral 101 denotes a pulse voltage generator, from which positive and negative pulse voltages are generated at fixed intervals.
  • the output terminal of the pulse voltage generator 101 is connected to a series circuit of the impedance element 15 and the detection coil 18 of the magnetic sensor 16.
  • the detection coil 18 is wound around a ferromagnetic core 17.
  • the positive and negative peak values of the voltage generated at both ends of the detection coil 18 are detected by a pair of positive voltage peak detectors 104 and negative voltage peak detectors 105.
  • the peak detection output from each of these peak detectors 104 and 105 is supplied to an adder 106 to be added and processed to obtain a measurement output V. Is sent.
  • a pulse voltage is supplied from the pulse voltage generator 101 to the detection coil 18 of the magnetic sensor 16, and the pulse voltage magnetizes the ferromagnetic material 103 b to a saturated state. Is done. Then, the ferromagnetic material 103 b as the magnetic field to be measured When the external magnetic fields intersect, a positive voltage and a negative voltage are generated in the coil 18 corresponding to the polarity and strength of the external magnetic field.
  • the pulse voltage is supplied to the coil 18 of the magnetic sensor 16 as described above, the power consumption is reduced as compared with the one that supplies the AC power, and power can be saved. For example, if the ratio between the pulse width of the pulse voltage and the pulse period T is (10 to 100) and is -T, the average power supplied to the magnetic sensor 16 becomes about 110 to 1Z100. It is possible to use a battery as a power source.
  • the relative sensitivity of the detection sensitivity of the minute magnetic flux hardly changes even if T / te is changed in a wide range of 2 to 100.
  • the sensitivity sharply decreases and it becomes difficult to save power.
  • FIG. 1 is a block diagram showing a schematic configuration of a magnetic detection device according to an embodiment of the present invention
  • FIG. 2 is a hysteresis characteristic and a magnetic permeability characteristic diagram of a core of a magnetic sensor of the device of the embodiment
  • FIG. 3 is a time chart showing the operation of the embodiment device.
  • FIG. 4 is a block diagram showing a schematic configuration of a conventional magnetic detection device
  • Fig. 5 is a time chart showing the operation of the conventional device.
  • Fig. 6 is a circuit diagram for explaining the measurement principle using a saturable magnetic sensor.
  • FIG. 7 is a diagram showing a power supply waveform to the coil and an output voltage waveform of the coil in FIG.
  • FIG. 8 is a block diagram for implementing the magnetic detection method of the present invention.

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  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Magnetic Variables (AREA)

Abstract

Un détecteur magnétique comprend un capteur magnétique (16) comportant une bobine de détection (18) sur un noyau ferromagnétique (17), un circuit produisant des signaux d'excitation (11) fournissant un courant alternatif d'excitation d'une valeur effective prédéterminée à la bobine de détection (18) du capteur magnétique (16) par l'intermédiaire d'un élément d'impédance (15) afin de saturer le noyau (17), à un circuit de formation de formes d'ondes (19) normalisant la forme d'onde du signal détecté obtenu à partir des deux bornes de la bobine de détection (18) à l'aide d'une valeur de seuil prédéteminée, ainsi qu'un compteur (20) mesurant la largeur d'impulsion de la sortie des signaux normalisés provenant du circuit de formation de formes d'ondes (19), afin de détecter l'intensité du champ magnétique extérieur en fonction du changement de la largeur d'impulsion provoqué par le champ magnétique extérieur rencontrant le capteur magnétique (16).
PCT/JP1991/000250 1990-02-28 1991-02-26 Procede et appareil de detection magnetique WO1991013366A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP4782290 1990-02-28
JP2/47822 1990-02-28
JP11528490A JPH03272483A (ja) 1990-02-28 1990-05-02 磁気検出装置
JP2/115284 1990-05-02
JP2278918A JP2617615B2 (ja) 1990-10-19 1990-10-19 磁気測定方法およびその装置
JP2/278918901019 1990-10-19

Publications (1)

Publication Number Publication Date
WO1991013366A1 true WO1991013366A1 (fr) 1991-09-05

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Application Number Title Priority Date Filing Date
PCT/JP1991/000250 WO1991013366A1 (fr) 1990-02-28 1991-02-26 Procede et appareil de detection magnetique

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WO (1) WO1991013366A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004061466A1 (fr) * 2002-12-26 2004-07-22 Masahiko Sumigama Capteur magnetique
FR3060757A1 (fr) * 2016-12-19 2018-06-22 Safran Electronics & Defense Capteur de courant a vanne de flux
CN115097223A (zh) * 2022-03-13 2022-09-23 中国人民解放军92728部队 一种周期脉冲辐射场场强的峰值检波测量方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5124269U (fr) * 1974-08-12 1976-02-23
US4290018A (en) * 1979-08-22 1981-09-15 Rockwell International Corporation Magnetic field strength measuring apparatus with triangular waveform drive means
US4303886A (en) * 1979-08-22 1981-12-01 Rockwell International Corporation Magnetic field strength measuring apparatus
US4305035A (en) * 1979-08-22 1981-12-08 Rockwell International Corporation Magnetic field amplitude detection sensor apparatus
JPS57199969A (en) * 1981-06-03 1982-12-08 Mitsubishi Electric Corp Magnetic field measuring device
JPS59141058A (ja) * 1984-01-20 1984-08-13 Hitachi Ltd 磁気検出器
JPH01308982A (ja) * 1989-04-28 1989-12-13 Nkk Corp 磁気測定方法及び磁気測定装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5124269U (fr) * 1974-08-12 1976-02-23
US4290018A (en) * 1979-08-22 1981-09-15 Rockwell International Corporation Magnetic field strength measuring apparatus with triangular waveform drive means
US4303886A (en) * 1979-08-22 1981-12-01 Rockwell International Corporation Magnetic field strength measuring apparatus
US4305035A (en) * 1979-08-22 1981-12-08 Rockwell International Corporation Magnetic field amplitude detection sensor apparatus
JPS57199969A (en) * 1981-06-03 1982-12-08 Mitsubishi Electric Corp Magnetic field measuring device
JPS59141058A (ja) * 1984-01-20 1984-08-13 Hitachi Ltd 磁気検出器
JPH01308982A (ja) * 1989-04-28 1989-12-13 Nkk Corp 磁気測定方法及び磁気測定装置

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004061466A1 (fr) * 2002-12-26 2004-07-22 Masahiko Sumigama Capteur magnetique
FR3060757A1 (fr) * 2016-12-19 2018-06-22 Safran Electronics & Defense Capteur de courant a vanne de flux
WO2018115032A1 (fr) * 2016-12-19 2018-06-28 Safran Electronics & Defense Capteur de courant a vanne de flux
CN110088636A (zh) * 2016-12-19 2019-08-02 赛峰电子与防务公司 具有磁通门的电流传感器
US10884028B2 (en) 2016-12-19 2021-01-05 Safran Electronics & Defense Current sensor with fluxgate
CN110088636B (zh) * 2016-12-19 2021-06-22 赛峰电子与防务公司 具有磁通门的电流传感器
CN115097223A (zh) * 2022-03-13 2022-09-23 中国人民解放军92728部队 一种周期脉冲辐射场场强的峰值检波测量方法

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