scholarly journals Improving the Detection Ability of Inductive Micro-Sensor for Non-Ferromagnetic Wear Debris

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1108
Author(s):  
Man Wang ◽  
Haotian Shi ◽  
Hongpeng Zhang ◽  
Dian Huo ◽  
Yucai Xie ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Steel Strip ◽  
Excitation Frequency ◽  
Signal Amplitude ◽  
Ferromagnetic Metal ◽  
Detection Sensitivity ◽  
Metal Debris ◽  
Detection Ability ◽  
Inductive Sensor ◽  
The Magnetic Field

The inductive debris sensor has been studied because of its wide application prospects in mechanical health monitoring. In order to ensure a high-precision detection performance, a comprehensive method to improve the detection sensitivity and detection ability of the inductive sensor for non-ferromagnetic metal debris is proposed. Based on the characteristics of the eddy current inside the metal, the change of the coil impedance caused by the metal debris is increased by enhancing the magnetic field strength and selecting the optimal excitation frequency. The impedance detection method involving inductance and resistance parameters is used to improve the detection limit of non-ferromagnetic metal debris. The experimental results verify that the magnetic field in the detection region can be enhanced by adding a silicon steel strip (paramagnetic material) in the central hole of the coil, thereby greatly improving the detection sensitivity of the inductive sensor, and the concentrated distribution of the magnetic field avoids the double-peak signals generated by a single particle. The characteristics of the signal amplitude of non-ferromagnetic debris with excitation frequency are studied. Higher inductance, resistance amplitudes, and signal-to-noise ratio (SNR) can be obtained by using a high-frequency alternating current. Compared with inductance parameter detection, resistance parameter detection can detect smaller non-ferromagnetic debris. Combining the detection results of the inductance and resistance parameters can effectively improve the sensor’s ability to detect non-ferromagnetic debris.

scholarly journals A Novel Impedance Micro-Sensor for Metal Debris Monitoring of Hydraulic Oil

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 150
Author(s):  
Hongpeng Zhang ◽  
Haotian Shi ◽  
Wei Li ◽  
Laihao Ma ◽  
Xupeng Zhao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Wear Debris ◽  
Detection Method ◽  
Silicon Steel ◽  
Detection Sensitivity ◽  
Normal Operation ◽  
Metal Debris ◽  
Hydraulic Oil ◽  
Steel Strips ◽  
The Magnetic Field

Hydraulic oil is the key medium for the normal operation of hydraulic machinery, which carries various wear debris. The information reflected by the wear debris can be used to predict the early failure of equipment and achieve predictive maintenance. In order to realize the real-time condition monitoring of hydraulic oil, an impedance debris sensor that can detect inductance and resistance parameters is designed and studied in this paper. The material and size of wear debris can be discriminated based on inductance-resistance detection method. Silicon steel strips and two rectangular channels are designed in the sensor. The silicon steel strips are used to enhance the magnetic field strength, and the double rectangular detection channels can make full use of the magnetic field distribution region, thereby improving the detection sensitivity and throughput of the sensor. The comparison experiment shows that the coils in series are more suitable for the monitoring of wear debris. By comparing and analyzing the direction and the presence or absence of the signal pulses, the debris sensor can detect and distinguish 46 µm iron particles and 110 µm copper particles. This impedance detection method provides a new technical support for the high-precision distinguishing measurement of metal debris. The sensor can not only be used for oil detection in the laboratory, but also can be made into portable oil detection device for machinery health monitoring.

scholarly journals An Impedance Sensor for Distinguishing Multi-Contaminants in Hydraulic Oil of Offshore Machinery

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1407
Author(s):  
Haotian Shi ◽  
Dian Huo ◽  
Hongpeng Zhang ◽  
Wei Li ◽  
Yuqing Sun ◽  
...  
Keyword(s):  
Steel Strip ◽  
Silicon Steel ◽  
Detection Sensitivity ◽  
Distribution Area ◽  
Metal Debris ◽  
Hydraulic Oil ◽  
Hydraulic Machinery ◽  
Steel Strips ◽  
Impedance Sensor ◽  
The Magnetic Field

The cleanliness of hydraulic oil can reflect the service life of the oil and the wear state of hydraulic machinery. An impedance sensor is proposed to distinguish multi-contaminants in hydraulic oil. The impedance sensor has two detection modes: the inductance-resistance mode is used to detect metal debris, and the capacitance mode is used to distinguish water droplets and air bubbles. By adding a built-in silicon steel strip and an external silicon steel strip with high magnetic permeability, the distribution area, strength, and uniformity of the magnetic field are enhanced to improve the detection sensitivity under inductance and resistance parameters. In addition, the silicon steel strips are used as electrode plates to introduce capacitance parameter detection. The experimental results show that the resistance detection method based on coil successfully improves the detection ability for non-ferromagnetic metal debris. The impedance sensor for distinguishing multi-contaminants in hydraulic oil can provide technical support for fault diagnosis of offshore hydraulic machinery.

scholarly journals Magnetorheological Fluids Behaviour in Oscillatory Compression Squeeze: Experimental Testing and Analysis

2019 ◽  
Vol 13 (4) ◽  
pp. 221-225
Author(s):  
Wojciech Horak ◽  
Marcin Szczęch ◽  
Bogdan Sapiński
Keyword(s):  
Magnetic Field ◽  
Volume Fraction ◽  
Experimental Testing ◽  
Magnetic Field Gradient ◽  
Particle Volume Fraction ◽  
Excitation Frequency ◽  
Magnetorheological Fluid ◽  
Density Level ◽  
Particle Volume ◽  
The Magnetic Field

Abstract This article deals with experimental testing of magnetorheological fluid (MRF) behaviour in the oscillatory squeeze mode. The authors investigate and analyse the influence of excitation frequency and magnetic field density level on axial force in MRFs that differ in particle volume fraction. The results show that, under certain conditions, the phenomenon of self-sealing can occur as a result of the magnetic field gradient and a vacuum in the working gap of the system.

scholarly journals Reconstruction of German Coastal Defense Line in 1942-1944 and Search for Military Historical Heritage Objects. Bolshoi Tyuters Island. Data of Geophysical Methods and Excavations.

2021 ◽  
pp. 144-161
Author(s):  
Aleksandr L'vovich Borisik ◽  
Evgeniy Vladimirovich Pyatigorskiy
Keyword(s):  
Magnetic Field ◽  
Sand Dunes ◽  
Geophysical Methods ◽  
Observation System ◽  
Metal Debris ◽  
Coastal Defense ◽  
Historical Heritage ◽  
Short Time ◽  
High Degree ◽  
The Magnetic Field

The article describes the results of full-scale geophysical 2017-2018 studies conducted with the purpose of detecting military historical heritage objects on Bolshoy Tyuters Island. Sand dunes located in the eastern part of the island were studied in a short time by detailed magnetic exploration with an observation step of about 1 m. The most interesting anomalies of the magnetic field were investigated with the georadiolocation method. The processed results provided for mapping the anomalous magnetic field and creating georadiolocation sections and a dimensional relief model which demonstrate anomalies related to German defense and are promising for further excavations. The pinpoint excavations of the identified anomalies made it possible to explain their nature and discover objects of historical value at depths of up to 5 m. Despite high "contamination" of the dunes with metal debris, the use of geophysical methods with a dense observation system made it possible to detect a large number of objects of military historical heritage and significantly reduce the volume of excavations. Linking of the German positions archival scheme at hand additionally provided for comparing the location of the objects found with symbols made on it. After systematization and generalization of all the information obtained during 4 years of research on the island, it is possible to reconstruct the system of German defense in the area of sand dunes with a high degree of reliability.

scholarly journals Improving Sensitivity of a Micro Inductive Sensor for Wear Debris Detection with Magnetic Powder Surrounded

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 440 ◽  
Author(s):  
Liankun Liu ◽  
Liang Chen ◽  
Saijie Wang ◽  
Yi Yin ◽  
Dazhuang Liu ◽  
...  
Keyword(s):  
Wear Debris ◽  
Detection Sensitivity ◽  
High Tech ◽  
Magnetic Powder ◽  
Research Papers ◽  
Inductive Sensor ◽  
Novel Method ◽  
Pass Through ◽  
The Magnetic Field ◽  
Inductive Signal

The inductive detection of wear debris in lubrication oil is an effective method to monitor the machine status. As the wear debris is usually micro scale, a micro inductive sensor is always used to detect them in research papers or high-tech products. However, the improvement of detection sensitivity for micro inductive sensors is still a great challenge, especially for early wear debris of 20 μm or smaller diameter. This paper proposes a novel method to improve the detection sensitivity of a micro inductive sensor. Regarding the magnetic powder surrounding the sensor, the magnetic field in the core of the sensor where the wear debris pass through would be enhanced due to the increased relative permeability. Thus, the inductive signal would be improved and the detection sensitivity would be increased. It is found that the inductive signal would linearly increase with increasing the concentration of the magnetic powder and this enhancement would also be effective for wear debris of different sizes. In addition, the detection limit of the micro inductive sensor used in our experiment could be extended to 11 μm wear debris by the proposed method.

Cardiac Vector Estimation in Fetal Magnetocardiography Using Realistic Approximations of the Volume Conductor

2012 ◽  
Author(s):  
Rong Tao ◽  
Elena-Anda Popescu ◽  
William B. Drake ◽  
David Jackson ◽  
Mihai Popescu
Keyword(s):  
Magnetic Field ◽  
Fetal Heart ◽  
Signal Amplitude ◽  
Signal Quality ◽  
Fetal Magnetocardiography ◽  
Vector Estimation ◽  
Fetal Electrocardiography ◽  
Cardiac Vector ◽  
To Receive ◽  
The Magnetic Field

Fetal magnetocardiography (fMCG) records the magnetic field generated by the electrical activity associated with the fetal cardiac muscle contraction and has emerged as an attractive tool for monitoring the fetal heart in-utero. The magnetic sensor array is placed above the maternal abdomen to receive the extremely weak magnetic signal of the fetal heart from 20 weeks of gestation onward. fMCG outperforms fetal electrocardiography (fECG) in its notably superior signal quality, as the magnetic field is considerably less affected by tissues with low electrical conductivity surrounding the fetal heart [1], which can drastically diminish the fECG signal amplitude.

scholarly journals Research on the Influence of Excitation Frequency on the Sensitivity in Metal Debris Detection with Inductor Sensor

2014 ◽  
Vol 6 ◽  
pp. 790615 ◽  
Author(s):  
Bendong Liu ◽  
Fangzhou Zhang ◽  
Desheng Li ◽  
Jiahui Yang
Keyword(s):  
Equivalent Circuit ◽  
Experimental Test ◽  
Detection System ◽  
Excitation Frequency ◽  
Reference Value ◽  
Ferromagnetic Metal ◽  
Test Results ◽  
Metal Debris ◽  
The Relationship ◽  
Higher Sensitivity

The nonferromagnetic debris is easier to be detected as the excitation frequency increases; however, the sensitivity of ferromagnetic metal debris decreases as the excitation frequency increases. This paper is aimed at finding a range of excitation frequency that fit both ferromagnetic metal debris detection and nonferromagnetic metal debris detection. The equivalent circuit of the metal debris detection system with microinductor sensor is analyzed in this paper. The formulae of relationship between the sensitivity and excitation frequency are achieved according to the equivalent circuit. The simulation model of metal debris detection with the microsensor coil is built with the Ansoft software. The equivalent inductance and the electromagnetic induction field of the microinductor sensor are simulated as the excitation frequency changed. The experimental test is carried out with the prototype of microinductor sensor. The simulation results and the test results are compared. The studies indicate that the relationship between the excitation frequency and the changing rate of sensor inductance can be described by the fitting formulae. A higher sensitivity can be obtained if a suitable excitation frequency is selected. These researches have reference value for the design of inductor sensor and the parameters setting in the experimental test.

scholarly journals Терагерцовая фотопроводимость в графене в магнитном поле

2020 ◽  
Vol 54 (4) ◽  
pp. 388
Author(s):  
Ю.Б. Васильев ◽  
С.Н. Новиков ◽  
С.Н. Данилов ◽  
С.Д. Ганичев
Keyword(s):  
Magnetic Field ◽  
Relaxation Time ◽  
Field Dependence ◽  
Electron Scattering ◽  
Terahertz Radiation ◽  
Magnetic Field Dependence ◽  
Signal Amplitude ◽  
Strong Increase ◽  
The Magnetic Field ◽  
Photoconductivity Signal

Abstract The terahertz photoconductivity in epitaxial graphene grown on SiC substrates is investigated in a magnetic field. The magnetic-field dependence of the photoresponse signal amplitude is examined at different electron densities, bias currents, and terahertz radiation intensities. The experimental results are explained well by a photoconductivity mechanism based on the heating of electrons by terahertz radiation. A strong increase in the photoconductivity signal with increasing magnetic field caused by an increase in the relaxation time due to the suppression of electron-electron scattering is observed.

Using the analytic signal amplitude to determine the location and depth of thin dikes from magnetic data

Geophysics ◽  
2015 ◽  
Vol 80 (1) ◽  
pp. J1-J6 ◽  
Author(s):  
Gordon R. J. Cooper
Keyword(s):  
Magnetic Field ◽  
Magnetic Anomaly ◽  
Magnetization Vector ◽  
Signal Amplitude ◽  
Analytic Signal ◽  
Magnetic Data ◽  
Local Minima ◽  
First Order ◽  
Higher Order Derivative ◽  
The Magnetic Field

A semiautomatic method to determine the location and depth of thin dykes is introduced. The ratio of analytic signal amplitudes of orders 0 and 1 of the magnetic anomaly from a thin dike was used to give the distance [Formula: see text] to the dike. Local minima of [Formula: see text] gave the depth to the dike, and the position of these minima gave its horizontal location. Because in the method we used just the magnetic field and its first-order derivatives, it was less sensitive to noise than were higher order derivative-based methods. Once the position of the dike has been determined, then its dip and susceptibility-thickness product can be calculated from the analytic signal amplitude, providing that the magnetization vector is known.

scholarly journals PT-Level High-Sensitivity Magnetic Sensor with Amorphous Wire

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 161 ◽  
Author(s):  
Dongfeng He
Keyword(s):  
Magnetic Field ◽  
Direct Current ◽  
High Sensitivity ◽  
Signal Amplitude ◽  
Magnetic Sensor ◽  
Resonant Circuit ◽  
Testing System ◽  
Amorphous Wire ◽  
Current Testing ◽  
The Magnetic Field

A picotesla (PT) level high-sensitivity magnetic sensor with amorphous wire was developed. The magnetic sensor was composed of a (Fe0.06Co0.94)72.5Si2.5B15 (FeCoSiB) amorphous wire with a coil wound around it. The amorphous wire had a diameter of 0.1 mm and a length of 5 mm. The coil was 30 turns. There was no electrical connection with the amorphous wire. The sensor was biased by an alternating current (AC) of about 1 MHz and a direct current (DC). To increase the sensitivity, a resonant circuit was used, and the signal amplitude of the magnetic sensor was increased 10 times from 10 mV/Gauss to about 100 mV/Gauss. The magnetic field resolution was improved 5 times from 30 pT/√Hz to 6 pT/√Hz. An eddy current testing system with a magnetic sensor was developed, and the artificial defects in an aluminum plate were evaluated.

Sign in / Sign up

Export Citation Format

Share Document