Sensitivity Model for Residence Times Difference Fluxgate Magnetometers Near Zero Magnetic Field

Research on magnetic sensors has been carried out in recent years to enhance sensing capability, enabling us to understand the Earth's magnetic field changes [1] with better sensitivities of 10 À10 to 10 À2 T. [2] Magnetic field sensors have been extensively investigated according to their operating principles and actions in various applications. Sensitivity and selectivity are the two essential properties crucial in the evolution of magnetic field sensors to achieve high fidelity outputs. The former is strengthened by increasing the sensor area and improvements to the planar surface with various Nano-materials. In contrast, the latter is improved by using multiple materials and techniques to enhance interfacial interactions.Magnetic sensors detect disturbances and changes in magnetic fields such as force, direction, and flux. It is a transducer that converts a magnetic field into an electrical voltage. There are several types of magnetic field sensors, each with its own sensitivity range. In addition to sensitivity, the temperature range, the physical size of the sensor, and its on-chip manufacturability must all be considered. Magnetic fields of less than 100 pT are extremely weak and far below the earth's magnetic field. Earth magnetic field sensors have a sensitivity range of 10 μT to a few micro-Tesla, while bias magnet field (high field) sensors have a sensitivity of more than 1 mT.Magnetic fields of less than 100 pT are extremely weak and far below the earth's magnetic field. Earth magnetic field sensors have a sensitivity range of 10 μT to a few micro-Tesla, while bias magnet field (high field) sensors have a sensitivity of more than 1 mT. The most sensitive low-field sensor is the superconducting quantum interference device (SQUID). It is based on Brian J. Josephson's research on a point-contact connection for measuring extremely low currents.The SQUID ring, the radio-frequency coil, and the big antenna loop are all superconducting components of the SQUID sensor. All three must be cooled to the point where they become superconducting. The SQUID itself is small, but the requirement for liquid helium cooling makes the entire apparatus big and hefty. Magnetoresistive sensors (MR) have a high sensitivity, are inexpensive to manufacture, and are small in size. However, they have poor noise performance and linearity, as well as a small dynamic range, making them unappealing and unsuitable for many low-noise applications. Furthermore, as the power usage is reduced, their sensitivity degrades.Search-coil or induction sensors are high-sensitivity, lowpower sensors, but their sensitivity decreases as the cross-section area decreases, making miniaturization ineffective. Because search coils can detect an alternating current magnetic field, they cannot detect a static magnetic field like the Earth's magnetic field. Magnetic sensors based on semiconductors, such as Hall-Effect sensors, magnetotransistors, and magnetodiodes, are very small in size. Because of its low manufacturing cost

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“…When encountered with the external magnetic field, the pluses were asymmetric and no longer possess zero value (Figure 12). [80][81][82]…”

Section: Rtd Fluxgate Sensormentioning

confidence: 99%

Fabrication Advancements in Integrated Fluxgate Sensors: A Mini Review

2022

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“…To increase the sensitivity of a RTD fluxgate magnetometer, Chen et al built a sensitivity model for RTD fluxgate magnetometers [ 16 ]. The model is clear and simple and can discuss the sensitivity of the RTD fluxgate and the coercivity of the magnetic core separately.…”

Section: Basic Researchmentioning

confidence: 99%

“…However, as the coercivity of the core is dependent on the driving condition and the relationship between them is unknown, it is difficult to calculate the sensitivity with Equation (5). What’s more, the sensitivity is also dependent on the target magnetic field as shown in Figure 8 [ 16 ]. It can be seen that only under low target magnetic field conditions, the sensitivity is nearly uniform (within ± 1000 nT), so the sensor can only accurately measure low fields [ 53 ].…”

Section: Basic Researchmentioning

confidence: 99%

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Recent Progress of Fluxgate Magnetic Sensors: Basic Research and Application

Wei

Liao

Zhang

et al. 2021

Sensors

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Fluxgate magnetic sensors are especially important in detecting weak magnetic fields. The mechanism of a fluxgate magnetic sensor is based on Faraday’s law of electromagnetic induction. The structure of a fluxgate magnetic sensor mainly consists of excitation windings, core and sensing windings, similar to the structure of a transformer. To date, they have been applied to many fields such as geophysics and astro-observations, wearable electronic devices and non-destructive testing. In this review, we report the recent progress in both the basic research and applications of fluxgate magnetic sensors, especially in the past two years. Regarding the basic research, we focus on the progress in lowering the noise, better calibration methods and increasing the sensitivity. Concerning applications, we introduce recent work about fluxgate magnetometers on spacecraft, unmanned aerial vehicles, wearable electronic devices and defect detection in coiled tubing. Based on the above work, we hope that we can have a clearer prospect about the future research direction of fluxgate magnetic sensor.

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“…The detection circuit and time difference during transmission are easily affected by environmental noise. The above situation causes abnormal time difference jumps, reducing the stability of the RTDfluxgate [11,12]. Therefore, it is necessary to estimate and deal with the gross error in time difference.…”

Section: Introductionmentioning

confidence: 99%

Research on a Time Difference Processing Method for RTD-Fluxgate Data Based on the Combination of the Mahalanobis Distance and Group Covariance

Pang,

Wang,

Yang

et al. 2023

Sensors

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During the measurement of magnetic fields, Residence Time Difference (RTD)-fluxgate sensors suffer from abnormal time difference jumps due to the random interference of magnetic core noise and environmental noise, which results in gross errors. This situation restricts the improvement of sensor accuracy and stability. In order to solve the above problems efficiently, a time difference gross error processing method based on the combination of the Mahalanobis distance (MD) and group covariance is presented in this paper, and the processing effects of different methods are compared and analyzed. The results of the simulation and experiment indicate that the proposed method is more advantageous in identifying the gross error in time difference. The signal-to-noise ratio for the time difference is improved by about 34 times, while the fluctuation of the Negative Magnetic Saturation Time (NMST) ΔTNMST is reduced by 95.402%, which significantly reduces the fluctuation of time difference and effectively improves the accuracy and stability of the sensor.

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Sensitivity Model for Residence Times Difference Fluxgate Magnetometers Near Zero Magnetic Field

Cited by 7 publications

References 15 publications

Fabrication Advancements in Integrated Fluxgate Sensors: A Mini Review

Fabrication Advancements in Integrated Fluxgate Sensors: A Mini Review

Recent Progress of Fluxgate Magnetic Sensors: Basic Research and Application

Research on a Time Difference Processing Method for RTD-Fluxgate Data Based on the Combination of the Mahalanobis Distance and Group Covariance

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