CN107121153A - High speed current vortex sensor - Google Patents
High speed current vortex sensor Download PDFInfo
- Publication number
- CN107121153A CN107121153A CN201710365550.7A CN201710365550A CN107121153A CN 107121153 A CN107121153 A CN 107121153A CN 201710365550 A CN201710365550 A CN 201710365550A CN 107121153 A CN107121153 A CN 107121153A
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- amplifier
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
- G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
Abstract
The present invention relates to range measurement, sensor, to propose high speed current vortex sensor, it is possible to increase the frequency response of sensor, the influence of transmission cable parasitic capacitance is eliminated, so as to improve the precision and stability of sensor measurement, increases measurement distance.Therefore, the technical solution adopted by the present invention is, high speed current vortex sensor is made up of search coil, high stable electric capacity, triaxial cable, and high frequency alternating current in coil produces alternating magnetic field, and produces in metal conductor measured the sensing current vortex of closure；Sensing current vortex acts on search coil in turn again, causes the LC resonance circuit characteristic impedances that itself and high stable electric capacity are constituted to change, and characteristic impedance change is transferred to distal end by triaxial cable, and the impedance changed in far-end measuring can be obtained measured.Present invention is mainly applied to range measurement occasion.
Description
Technical field
The present invention relates to range measurement, sensor, specifically, it is related to high speed current vortex sensor.
Background technology
Current vortex sensor be the eddy current effect that produces in metallic conductor using alternating magnetic field to measure one
Kind of sensor, it is high with sensitivity, the advantages of non-cpntact measurement and strong antijamming capability, it is widely used in displacement, vibration and work
The measurement that part is damaged and deformed.In actually measurement, probe is made up of sensor coil and shell, commonly uses sensor coil and preceding storing
Electric capacity composition LC resonance in big circuit, measured information is obtained by the skew for measuring resonance point.In order to reduce oscillator
Load, again need to be in LC resonance circuits one end series resistance, so the frequency response of sensor is typically relatively low, bandwidth highest tens
KHz.On the other hand, probe is connected with signal processing circuit by coaxial cable, and the parasitic capacitance of cable causes measurement result
It is inaccurate, so that precision and resolution ratio are influenceed, and the more remote influence of measurement distance is more obvious.
The content of the invention
To overcome the deficiencies in the prior art, the present invention is directed to propose high speed current vortex sensor, it is possible to increase sensor
Frequency response, eliminates the influence of transmission cable parasitic capacitance, so that the precision and stability of sensor measurement is improved, increase measurement
Distance.Therefore, the technical solution adopted by the present invention is, high speed current vortex sensor, by search coil, high stable electric capacity, three same
Shaft cable is constituted, and the high frequency alternating current in coil produces alternating magnetic field, and produces in metal conductor measured the sensing of closure
Current vortex；Sensing current vortex acts on search coil in turn again, and the LC resonance circuits for causing itself and high stable electric capacity to constitute are special
Property impedance change, characteristic impedance change by triaxial cable is transferred to distal end, far-end measuring change impedance
Obtain measured.
The external shielding layer of triaxial cable connects the earth, the driving electricity being made up of amplifier op, electric capacity C1, driving source and resistance R1
The floating ground in road, amplifier in-phase input end is drive circuit reference point, produces driving source connection the earth and the driving of high frequency alternating current
Circuit reference point；The cored wire connection amplifier op of triaxle cable inverting input；Internal shield connection amplifier op homophase input
End；Amplifier output voltage uo amplitudes or the measured change of frequency reflection, by subsequent process circuit be solve it is measured.
The alternating voltage that driving source is produced is ui, and its frequency is ω, then output voltage is
Wherein j is imaginary number, and j2=-1.
The external shielding layer e and drive circuit of triaxial cable connect the earth altogether, and cable passes through a coaxial electrical with drive circuit
Cable is connected.In one end of transmission cable, the screen layer of coaxial cable connects the internal shield of cable, and the cored wire of coaxial cable connects cable
Cored wire；In drive circuit one end, the screen layer of coaxial cable connects amplifier op in-phase input end, and coaxial cable core wire connects amplifier
Op reverse input end, coaxial cable is around lopping, as the secondary coil of transformer, to transmit the high-frequency alternating of driving source generation
Electric current, amplifier output voltage uo amplitudes or the measured change of frequency reflection, by subsequent process circuit be solve it is measured.
The alternating voltage that the cored wire of coaxial cable and screen layer two ends sense is respectively ui9 and ui10, then has ui9=
Ui10, and output voltage uo is
The features of the present invention and beneficial effect are：
The present invention is transmitted by the electric capacity in sensor probe two ends high stable in parallel with triaxial cable, is tied
Drive cable technique is closed, current vortex sensor bandwidth can be brought up to hundreds of KHzs, and eliminate the parasitic capacitance of transmission cable
Influence, realizes high accuracy, high stability and telemeasurement.
Brief description of the drawings：
Fig. 1 is high speed current vortex sensor of the present invention probe schematic diagram.Wherein 1 is search coil, and 2 be high stable electricity
Hold, 3 be triaxial cable, and a is the cored wire of cable 3, and b is the internal shield of cable 3, and e is the external shielding layer of cable 3.
Fig. 2 is cable drive scheme 1.Wherein 4 be high frequency pumping source, and 5 be the earth, and 6 be the reference point of drive circuit, that is, is floated
Ground.Op is operational amplifier, and C1 is electric capacity, and R1 is resistance.
Fig. 3 is cable drive scheme 2.Wherein 7 be coaxial cable, and m is 7 cored wire, and n is 7 screen layer, and 8 be transformer.
Fig. 4 is the equivalent circuit of cable drive scheme 1.Wherein L is the equivalent inductance of search coil 1, and C is high stable electric capacity
2, Cd1 for triaxial cable 3 cored wire a and internal shield b between electric capacity, Cd2 for triaxial cable 3 internal shield b and
Electric capacity between external shielding layer e, Cg is the electric capacity between the earth 5 and floating ground 6.
Fig. 5 is the equivalent circuit of cable drive scheme 2.Wherein 9 height sensed for the internal shield m two ends of coaxial cable 7
Frequency alternating voltage, 10 high-frequency alternating voltages sensed for the external shielding layer n two ends of coaxial cable 7, Cd3 is the core of coaxial cable 7
Electric capacity between line m and internal shield n.
Embodiment
The invention belongs to sensor field.Specifically, the present invention relates to a kind of current vortex sensor, in sensor probe
Coil-end parallel connection high stable resonant capacitance, and combine the shadow that Drive cable technique eliminates parasitic capacitance between cored wire and screen layer
Ring, measured high speed, accurate and telemeasurement can be achieved.
The present invention proposes a kind of current vortex sensor design, and resonant capacitance is connected in parallel on into sensor probe end, makes series electrical
Resistance is zero Europe, to improve the frequency response of sensor；It is transmitted, with reference to Drive cable technique, is eliminated using triaxial cable
The influence of transmission cable parasitic capacitance, to improve the precision and stability of sensor measurement, increases measurement distance.
The technical solution adopted by the present invention is in the electric capacity of sensor probe two ends high stable in parallel, and to use three coaxial electricals
Cable is transmitted, with reference to Drive cable technique, realizes wide bandwidth, high-precision and high-stability and telemeasurement.Fig. 1 show biography
Sensor probe scheme.High frequency alternating current in coil 1 produces alternating magnetic field, and produces in metal conductor measured the sense of closure
Answer current vortex；Sensing current vortex acts on search coil 1 in turn again, the LC resonance electricity for causing itself and high stable electric capacity 2 to constitute
Road characteristic impedance changes, and the impedance by measuring change can be obtained measured.Probe passes through triaxial cable 3 and signal
Process circuit is connected, and wherein a is the cored wire of cable 3, and b is the internal shield of cable 3, and e is the external shielding layer of cable 3.
Fig. 2 show cable drive scheme 1.The external shielding layer e of triaxial cable 3 connects the earth 5, is made up of op, C1 and R1
The floating ground of drive circuit, 6 be its circuit reference point.Produce the connection of driving source 4 the earth 5 and drive circuit ginseng of high frequency alternating current
Examination point 6；The cored wire concatenation operation amplifier op of triaxle cable 3 inverting input；Internal shield b connections op homophase input
End.Amplifier output voltage uo amplitudes or the measured change of frequency reflection, can be solved measured by subsequent process circuit.
Fig. 3 show drive scheme 2, and the external shielding layer e and drive circuit of triaxial cable 3 connect the earth 5, and cable 3 altogether
It is connected with drive circuit by a coaxial cable 7.In one end of transmission cable 3, the screen layer n of coaxial cable 7 connects the interior of cable 3
Screen layer b, the cored wire m of coaxial cable 7 meets the cored wire a of cable 3；In drive circuit one end, 7 screen layer n connects the same of amplifier op
Phase input, cored wire m connects op reverse input end.Coaxial cable 7 is sharp to transmit as the secondary coil of transformer 8 around lopping
Encourage the high frequency alternating current of the generation of source 4.Amplifier output voltage uo amplitudes or the measured change of frequency reflection, pass through subsequent treatment electricity
Road can solve measured.
The present invention is described in detail with reference to the accompanying drawings and detailed description.
Fig. 1 show high speed current vortex sensor probe.High frequency alternating current generation alternating magnetic field in coil 1, and
The sensing current vortex of closure is produced in metal conductor measured；Sensing current vortex again act on search coil 1 in turn, cause itself and
The LC resonance circuit characteristic impedances that high stable electric capacity 2 is constituted change, and the impedance by measuring change can be obtained measured.
Probe is connected by triaxial cable 3 with signal processing circuit.
Fig. 2 show cable drive scheme 1.The external shielding layer e of triaxial cable 3 connects the earth 5, is made up of op, C1 and R1
The floating ground of drive circuit, 6 be its circuit reference point.Produce the connection of driving source 4 the earth 5 and drive circuit ginseng of high frequency alternating current
Examination point 6；The cored wire concatenation operation amplifier op of triaxle cable 3 inverting input；Internal shield b connections op homophase input
End.Amplifier output voltage uo amplitudes or the measured change of frequency reflection, can be solved measured by subsequent process circuit.The drive
The equivalent circuit of dynamic scheme is as shown in Figure 4.If the alternating voltage that driving source 4 is produced is ui, its frequency is ω, then output voltage is
Wherein j is imaginary number, and j2=-1.Due to being 0 with the resistance of LC resonant series, the frequency response of circuit is up to 100,000
Hertz, and from (1) formula, output voltage is not by between parasitic capacitance Cd1, Cd2 and the earth 5 and floating ground 6 of triaxial cable 3
Electric capacity Cg influence.Amplifier output voltage uo amplitudes or the measured change of frequency reflection, can be solved by subsequent process circuit
Go out measured.
Fig. 3 show drive scheme 2, and the external shielding layer e and drive circuit of triaxial cable 3 connect the earth 5, and cable 3 altogether
It is connected with drive circuit by a coaxial cable 7.In one end of transmission cable 3, the screen layer n of coaxial cable 7 connects the interior of cable 3
Screen layer b, the cored wire m of coaxial cable 7 meets the cored wire a of cable 3；In drive circuit one end, 7 screen layer n connects the same of amplifier op
Phase input, cored wire m connects op reverse input end.Coaxial cable 7 is sharp to transmit as the secondary coil of transformer 8 around lopping
Encourage the high frequency alternating current of the generation of source 4.It is located at the alternating voltage 9 and 10 of cored wire m and screen layer n the two ends sensing of coaxial cable 7
Respectively ui9 and ui10, then have ui9=ui10, and output voltage uo is
From (2) formula, output voltage is not by parasitic capacitance Cd1, Cd2 and the parasitism electricity of coaxial cable 7 of coaxial cable 3
Hold Cd3 influence.Amplifier output voltage uo amplitudes or the measured change of frequency reflection, by subsequent process circuit can solve by
Measurement.
Claims (5)
1. a kind of high speed current vortex sensor, it is characterized in that, it is made up of search coil, high stable electric capacity, triaxial cable, coil
In high frequency alternating current produce alternating magnetic field, and produce in metal conductor measured the sensing current vortex of closure；Induced electricity whirlpool
Stream acts on search coil in turn again, causes the LC resonance circuit characteristic impedances that itself and high stable electric capacity are constituted to change,
Characteristic impedance change is transferred to distal end by triaxial cable, and the impedance changed in far-end measuring can be obtained measured.
2. high speed current vortex sensor as claimed in claim 1, it is characterized in that, the external shielding layer of triaxial cable connects the earth,
The floating ground of drive circuit being made up of amplifier op, electric capacity C1, driving source and resistance R1, amplifier in-phase input end refers to for drive circuit
Point, produces the driving source connection the earth and drive circuit reference point of high frequency alternating current；The cored wire connection amplifier op of triaxle cable
Inverting input；Internal shield connection amplifier op in-phase input end；Amplifier output voltage uo amplitudes or frequency reflection are tested
Amount change, by subsequent process circuit be solve it is measured.
3. high speed current vortex sensor as claimed in claim 2, it is characterized in that, the alternating voltage that driving source is produced is ui, its
Frequency is ω, then output voltage is
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Wherein j is imaginary number, and j2=-1.
4. high speed current vortex sensor as claimed in claim 1, it is characterized in that, the external shielding layer e of triaxial cable and driving
Circuit connects the earth altogether, and cable is connected with drive circuit by a coaxial cable.In one end of transmission cable, the screen of coaxial cable
The internal shield that layer connects cable is covered, the cored wire of coaxial cable connects the cored wire of cable；In drive circuit one end, the shielding of coaxial cable
Layer connects amplifier op in-phase input end, and coaxial cable core wire connects amplifier op reverse input end, and coaxial cable is used as change around lopping
The secondary coil of depressor, to transmit the high frequency alternating current of driving source generation, amplifier output voltage uo amplitudes or frequency reflection quilt
Measurement change, by subsequent process circuit be solve it is measured.
5. high speed current vortex sensor as claimed in claim 4, it is characterized in that, the cored wire of coaxial cable and the sense of screen layer two ends
The alternating voltage answered is respectively ui9 and ui10, then has ui9=ui10, and output voltage uo is
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1
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710365550.7A CN107121153A (en) | 2017-05-22 | 2017-05-22 | High speed current vortex sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710365550.7A CN107121153A (en) | 2017-05-22 | 2017-05-22 | High speed current vortex sensor |
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| CN107121153A true CN107121153A (en) | 2017-09-01 |
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| CN201710365550.7A Pending CN107121153A (en) | 2017-05-22 | 2017-05-22 | High speed current vortex sensor |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109239911A (en) * | 2018-07-12 | 2019-01-18 | 中国科学院国家天文台南京天文光学技术研究所 | Adaptive subaperture based on electric eddy current measurement controls equipment |
| CN110426064A (en) * | 2019-07-18 | 2019-11-08 | 东南大学 | Wireless sourceless sensor and wireless and passive method for sensing |
| CN112729096A (en) * | 2020-12-30 | 2021-04-30 | 清华大学 | Metal film thickness measuring device for chemical mechanical polishing |
| CN113092546A (en) * | 2021-05-24 | 2021-07-09 | 天津大学 | Crude oil water content measurement capacitance sensor probe based on active shielding structure |
| CN114089249A (en) * | 2021-11-26 | 2022-02-25 | 广东美的暖通设备有限公司 | Filter circuit, eddy current sensor, debugging method and debugging device |
| CN114167130A (en) * | 2021-12-17 | 2022-03-11 | 常州同惠电子股份有限公司 | Voltage detection circuit and method of precision voltmeter for measuring high internal resistance power supply |
| CN114166106A (en) * | 2021-11-03 | 2022-03-11 | 重庆材料研究院有限公司 | Magnetostrictive displacement sensor |
| CN114812618A (en) * | 2021-12-24 | 2022-07-29 | 中国科学院长春光学精密机械与物理研究所 | Frequency point noise suppression system |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109239911A (en) * | 2018-07-12 | 2019-01-18 | 中国科学院国家天文台南京天文光学技术研究所 | Adaptive subaperture based on electric eddy current measurement controls equipment |
| CN110426064A (en) * | 2019-07-18 | 2019-11-08 | 东南大学 | Wireless sourceless sensor and wireless and passive method for sensing |
| CN110426064B (en) * | 2019-07-18 | 2021-07-20 | 东南大学 | Wireless passive sensor and wireless passive sensing method |
| CN112729096A (en) * | 2020-12-30 | 2021-04-30 | 清华大学 | Metal film thickness measuring device for chemical mechanical polishing |
| CN113092546A (en) * | 2021-05-24 | 2021-07-09 | 天津大学 | Crude oil water content measurement capacitance sensor probe based on active shielding structure |
| CN114166106A (en) * | 2021-11-03 | 2022-03-11 | 重庆材料研究院有限公司 | Magnetostrictive displacement sensor |
| CN114089249A (en) * | 2021-11-26 | 2022-02-25 | 广东美的暖通设备有限公司 | Filter circuit, eddy current sensor, debugging method and debugging device |
| CN114167130A (en) * | 2021-12-17 | 2022-03-11 | 常州同惠电子股份有限公司 | Voltage detection circuit and method of precision voltmeter for measuring high internal resistance power supply |
| CN114167130B (en) * | 2021-12-17 | 2024-04-02 | 常州同惠电子股份有限公司 | Voltage detection circuit and method for precise voltmeter for high-internal-resistance power supply measurement |
| CN114812618A (en) * | 2021-12-24 | 2022-07-29 | 中国科学院长春光学精密机械与物理研究所 | Frequency point noise suppression system |
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Application publication date: 20170901 |