CN-121995279-A - Magnetic field measuring method, system, equipment and medium based on phase difference magnetometer

CN121995279ACN 121995279 ACN121995279 ACN 121995279ACN-121995279-A

Abstract

The invention belongs to the technical field of magnetic field measurement, discloses a method, a system, equipment and a medium for measuring a magnetic field by using a magnetometer based on a phase difference, and aims to solve the problems that the existing multi-probe magnetic gradiometer system is high in complexity and cost, and the measurement stability is easily influenced by the performance and the synchronization precision of a frequency meter. The method comprises the steps of obtaining a corresponding relation between a phase difference and voltage through a first magnetometer and a signal generating device, determining a conversion coefficient between magnetic field intensity and voltage, connecting an output signal of a second magnetometer to a radio-frequency coil of the first magnetometer, obtaining the phase difference between the output signal of the second magnetometer and the output signal of the first magnetometer, converting the phase difference into a second voltage, and calculating the magnetic field intensity of a magnetic field to be detected according to the second voltage and the conversion coefficient. The invention does not need a multichannel synchronous acquisition technology and a complex differential circuit, and greatly simplifies the system structure, reduces the cost and improves the measurement stability while keeping the noise suppression level equivalent to that of the traditional magnetic gradient technology.

Inventors

WANG YIFAN
QIAN DUN
ZENG MINGQUAN
LI WENBO
YANG GUOQING
ZHOU QIAN
LI GUOZHU

Assignees

国网浙江省电力有限公司电力科学研究院

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. A method for measuring a magnetic field by a magnetometer based on a phase difference, comprising the steps of: S1, acquiring a corresponding relation between a phase difference and a voltage through a first magnetometer and a signal generating device so as to determine a conversion coefficient between magnetic field intensity and the voltage; S2, an output signal of a second magnetometer is connected into a radio frequency coil of the first magnetometer, a phase difference between the output signal of the second magnetometer and the output signal of the first magnetometer is obtained, and the phase difference is converted into a second voltage; s3, calculating the magnetic field strength of the magnetic field to be measured according to the second voltage and the conversion coefficient.
2. The method of measuring a magnetic field using a phase difference based magnetometer of claim 1, wherein step S1 comprises: s11, in a controllable magnetic field environment, measuring an artificial controllable magnetic field by using the first magnetometer, and measuring the frequency of the artificial controllable magnetic field output by the first magnetometer output module by using a frequency meter; S12, disconnecting the radio frequency coil of the first magnetometer from an output module thereof, connecting the signal generating device to the radio frequency coil, and carrying out sweep frequency output by taking the artificial controllable magnetic field frequency as a central frequency; s13, taking an output signal of the signal generating device as a reference signal of a phase-locked amplifier, taking a signal output by the first magnetometer output module as an input signal of the phase-locked amplifier, measuring a phase difference between the reference signal and the input signal by using the phase-locked amplifier, and converting the phase difference into a first voltage; S14, calculating a conversion coefficient according to the magnetic field intensity of the artificial controllable magnetic field and the first voltage.
3. A method of measuring a magnetic field using a phase difference based magnetometer according to claim 2 wherein: The coil is placed in the magnetic shielding barrel, and an external environment magnetic field is isolated through the magnetic shielding barrel; and connecting a current source with the coil, and driving the coil through the current source to generate the artificial controllable magnetic field.
4. A method of measuring a magnetic field using a phase difference based magnetometer according to claim 3 wherein: the coil is a moment-free coil or a Helmholtz coil.
5. The method of measuring a magnetic field using a phase difference based magnetometer of claim 1, wherein step S2 comprises: S21, disconnecting the radio frequency coil of the first magnetometer from an output module of the radio frequency coil, and connecting the output end of the second magnetometer with the radio frequency coil of the first magnetometer; S22, taking the output signal of the second magnetometer as a reference signal of a phase-locked amplifier, taking the output signal of the first magnetometer output module as an input signal of the phase-locked amplifier, measuring the phase difference between the reference signal and the input signal by using the phase-locked amplifier, and converting the phase difference into a second voltage; s23, calculating the magnetic field strength of the magnetic field to be measured according to the second voltage and the conversion coefficient.
6. The phase difference based magnetometer method of claim 1, wherein: the first magnetometer and the second magnetometer are self-excited light pump magnetometers.
7. The method of claim 6, wherein the first magnetometer is positioned in a direction comprising any of: along the direction of magnetic field lines, perpendicular to the direction of magnetic field lines, or intersecting the direction of magnetic field lines.
8. A magnetometer-based magnetic field system for implementing a magnetometer-based magnetic field method according to any one of claims 1 to 7.
9. A computer device comprising a memory, a processor and a computer program, wherein the computer program when executed by the processor implements the magnetometer magnetic field measurement method of any one of claims 1 to 7.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements a magnetometer magnetic field measurement method according to any of claims 1 to 7.

Description

Magnetic field measuring method, system, equipment and medium based on phase difference magnetometer Technical Field The invention belongs to the technical field of magnetic field measurement, and particularly relates to a method, a system, equipment and a medium for measuring a magnetic field by using a magnetometer based on a phase difference. Background The optical pump magnetometer is a quantum magnetic sensor based on the alkali metal atom Zeeman effect, has the characteristics of high precision and high sensitivity, and is widely applied to the fields of geological exploration, national defense construction, medical examination and the like. The single-probe optical pump magnetometer can only measure scalar information of a magnetic field, is easily influenced by factors such as geomagnetic daily variation, environmental magnetic noise and the like in practical application, and has limited measurement accuracy. In order to suppress the interference of environmental magnetic field noise, two or more probes of optical pump magnetometers are generally adopted to form a magnetic gradiometer, and the frequency of signals output by a plurality of probes is measured and subjected to differential processing to eliminate common mode background noise, so that a purer magnetic field measurement result is obtained. At present, a magnetic gradient measurement technology based on an optical pump magnetometer is mature, and is widely applied to magnetic total field gradient measurement. For example, the SeaSPY ocean magnetometer of Canadian MARINE MAGNETICS is used for realizing gradient detection by adopting four independent magnetometers, the absolute precision can reach 0.2nT, the CS-3 cesium light pump magnetometer produced by Canadian Scintrex is operated in the range of 15000nT to 105000nT, the gradient difference reaches 40000nT/m, and the sensitivity is 0.6 pT/. V.Hz rms. The technical schemes all adopt a multi-probe structure, and environmental noise is restrained through a frequency difference mode. However, existing magnetic gradient measurement techniques have significant limitations. The core measurement principle of the optical pump magnetometer is to determine the magnetic field intensity by measuring the larmor frequency of atomic gas under the action of an external magnetic field, so that in a multi-probe gradient measurement system, the output frequencies of a plurality of probes are required to be measured simultaneously and differential operation is carried out on the output frequencies. This requires the use of high precision multichannel frequency meters and places very stringent demands on the accuracy of the acquisition of the frequency meters, multichannel time synchronicity, differential algorithms, etc. The above factors result in a multi-probe magnetic gradiometer system that is highly complex, costly, and measurement stability is susceptible to frequency meter performance and synchronization accuracy. Disclosure of Invention Based on the above-mentioned drawbacks and disadvantages of the prior art, it is an object of the present invention to at least solve one or more of the above-mentioned problems of the prior art, in other words, to provide a method, a system, an apparatus and a medium for measuring a magnetic field by using a magnetometer based on a phase difference, which satisfies one or more of the above-mentioned requirements, so as to achieve the purposes of simplifying the structure of the magnetic measurement system, reducing the cost of the apparatus, improving the measurement stability, and simultaneously effectively suppressing the noise of the environmental magnetic field. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the present invention provides a method for measuring a magnetic field by a magnetometer based on a phase difference, comprising the steps of: S1, acquiring a corresponding relation between a phase difference and a voltage through a first magnetometer and a signal generating device so as to determine a conversion coefficient between magnetic field intensity and the voltage; S2, an output signal of a second magnetometer is connected into a radio frequency coil of the first magnetometer, a phase difference between the output signal of the second magnetometer and the output signal of the first magnetometer is obtained, and the phase difference is converted into a second voltage; s3, calculating the magnetic field strength of the magnetic field to be measured according to the second voltage and the conversion coefficient. As a preferred embodiment, step S1 includes: s11, in a controllable magnetic field environment, measuring an artificial controllable magnetic field by using the first magnetometer, and measuring the frequency of the artificial controllable magnetic field output by the first magnetometer output module by using a frequency meter; S12, disconnecting the radio frequency coil of