scholarly journals Calibration of a Measuring Device to Determine Specific Saturation Magnetization by A Special Coil

2014 ◽  
Vol 65 (4) ◽  
pp. 262-264
Author(s):  
Michal Ulvr
Keyword(s):  
Saturation Magnetization ◽  
Standard Method ◽  
Magnetic Moment ◽  
Calibration Method ◽  
Ferromagnetic Materials ◽  
Expanded Uncertainty ◽  
Measuring Device ◽  
Sources Of Uncertainty ◽  
Specific Saturation Magnetization ◽  
Alternative Method

Abstract Specific saturation magnetization σS is an important parameter of ferromagnetic materials. It is in principle independent of the structure and shape of the sample. There are two ways to calibrate devices for determining σS: the standard method, using a calibrated magnetic moment standard, or an alternative method, using a special moment coil. This paper presents a calibration method used at Czech Metrology Institute for calibration of Koerzimat 1.096 using a special moment coil. Special attention is given to a description of the special moment coils used for Koerzimat 1.096 calibration, and to analysis of sources of uncertainty. Calibration expanded uncertainty of 0.4 up to 0.6 % can be achieved using this method.

Comparison of test methods for measuring the net buoyant force of buoyant materials

2020 ◽  
Vol 24 (2) ◽  
pp. 147-161 ◽  
Author(s):  
Nga-wun Li ◽  
Chu-po Ho ◽  
Kit-lun Yick ◽  
Jin-yun Zhou
Keyword(s):  
Traditional Method ◽  
Functional Performance ◽  
Test Methods ◽  
Measuring System ◽  
Small Scale ◽  
Water Safety ◽  
Buoyant Force ◽  
Measuring Device ◽  
Content Type ◽  
Alternative Method

Purpose Net buoyant force is a crucial factor affecting the functional performance of clothing for water safety. This study aims to develop an alternative method for measuring the net buoyant force of various buoyant materials such as buoyant fabrics, on a small scale in a more accurate and efficient way than the existing method. Design/methodology/approach The net buoyant forces of buoyant materials with different thicknesses and forms were determined and compared using three methods. In Method 1, the traditional method involving mathematical calculations was used; Method 2 involved using the buoyancy-measuring device from the study of Jin et al. (2018) and Method 3 involved using an alternative buoyancy-measuring system that simulates the actual situation of using buoyant swimwear by measuring the force needed to submerge the buoyant material in water at a standard depth. The net buoyant forces of 22 buoyant materials were measured and compared to test these three methods. The accuracy, reproducibility, sensitivity and validity of these methods were then statistically compared. Findings The results obtained with the alternative buoyancy-measuring system had higher accuracy, reproducibility and validity than the results obtained through mathematical calculations. The sensitivity of the buoyancy-measuring system (Methods 2 and 3) was higher than that of the traditional method involving calculations (Method 1). Originality/value An alternative method is proposed to measure the net buoyant force of buoyant materials on a small scale with higher accuracy, reproducibility and sensitivity.

Ferromagnetism in lightly Gd doped GaN: The role of defects

2011 ◽  
Vol 1290 ◽  
Author(s):  
J. K. Mishra ◽  
S. Dhar ◽  
M. A. Khaderabad ◽  
O. Brandt
Keyword(s):  
Magnetic Properties ◽  
Molecular Beam Epitaxy ◽  
Saturation Magnetization ◽  
Magnetic Moment ◽  
Molecular Beam ◽  
Defect Density ◽  
Defect Cluster ◽  
Clear Correlation ◽  
Defect Band

ABSTRACTGd:GaN layers grown with different Gd concentrations by molecular beam epitaxy (MBE) are studied using photoconductivity and photo-thermoelectric power spectroscopy. Our study reveals that the incorporation of Gd produces a large concentration of acceptor-like defects in the GaN lattice. The defect band is found to be located ~450meV above the valence band. Moreover, the concentration of defects is found to increase with the Gd concentration. The effect of annealing on the structural and the magnetic properties of GaN implanted with Gd is also investigated. A clear correlation between the saturation magnetization and the defect density is observed in implanted samples. The colossal magnetic moment per Gd ion and the ferromagnetism observed in this material is explained in terms of the formation of giant defect cluster around each Gd ion.

A practical calibration process using partial information for a commercial Stewart platform

Robotica ◽  
2002 ◽  
Vol 20 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Kok-Soon Chai ◽  
Ken Young ◽  
Ian Tuersley
Keyword(s):  
Partial Information ◽  
Calibration Method ◽  
Stewart Platform ◽  
Low Noise ◽  
Production Environment ◽  
Leg Length ◽  
Measuring Device ◽  
Calibration Methods ◽  
Noise Data ◽  
Computation Algorithms

Most of the calibration methods proposed for the Stewart platform require complex computation or low noise data for the platform's accuracy to be determined. They are not suitable for practical use in a production environment, where the measurement and calibration method should be simple and robust. Using an external laser measuring device to determine the actual accuracy of a Stewart platform, a practical and simple leg length compensating calibration method, that improves the accuracy of the Stewart platform by a magnitude of around 7, is proposed. The procedures and computation algorithms of the calibration method are shown.

Synthesis of CaO-Na2O-Fe2O3-FeO-B2O3-SiO2 Glass-Ceramics for Hyperthermia Application by Aqueous Solution-Melt Method

2012 ◽  
Vol 535-537 ◽  
pp. 861-865
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang ◽  
Wen He
Keyword(s):  
Aqueous Solution ◽  
Saturation Magnetization ◽  
Electric Furnace ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Vibrating Sample Magnetometer ◽  
Sio2 System ◽  
Specific Saturation Magnetization ◽  
Heat Treated ◽  
Molecular Scale

Based on the CaO-Na2O-Fe2O3-FeO-B2O3-SiO2 system, the ferrimagnetic glass-ceramic has been prepared for hyperthermia application by aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 2h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD, TG, as well as Vibrating Sample Magnetometer (VSM). The glass-ceramics with B2O3=3.0wt% show a strong magnetic, which contains highest value of specific saturation magnetization of 28.34A•m2/kg.

Preparation and Characterization of SrO-Na2O-Fe2O3-FeO-P2O5-SiO2 Ferrimagnetic Glass-Ceramics for Hyperthermia Application

2012 ◽  
Vol 557-559 ◽  
pp. 1612-1617
Author(s):  
Jian An Liu ◽  
Xue Na Yang ◽  
Mei Mei Zhang ◽  
Wen He
Keyword(s):  
Aqueous Solution ◽  
Saturation Magnetization ◽  
Electric Furnace ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Vibrating Sample Magnetometer ◽  
Specific Saturation Magnetization ◽  
Heat Treated ◽  
Molecular Scale

The ferrimagnetic glass-ceramic based on SrO-Na2O-Fe2O3-FeO-P2O5-SiO2 system was prepared for hyperthermia application using aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 1h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD, TEM, as well as vibrating sample magnetometer (VSM). The glass-ceramics with P2O5=5.0wt% show a strong magnetic, which contains highest value of specific saturation magnetization of 24.89A•m2/kg.

Inductive displacement gauge

1980 ◽  
Vol 239 (2) ◽  
pp. G128-G132
Author(s):  
Y. J. Kingma ◽  
K. L. Bowes ◽  
M. S. Kocylowski ◽  
J. Szmidt
Keyword(s):  
Muscle Tissue ◽  
Strain Gauge ◽  
Contractile Activity ◽  
Low Cost ◽  
Strain Gauges ◽  
Secondary Effects ◽  
Measuring Device ◽  
Alternative Method ◽  
Very High ◽  
Type Transducer

Strain gauges are often used for the measurement of contractile activity of muscle tissue. In these cases the strain gauge is used as a force measuring device. Because of its stiffness, the strain-gauge-type transducer resists changes in length produced by contraction, and this could cause secondary effects. This paper describes an alternative method to evaluate contractions. Displacement rather than force is measured. The device offers very little resistance to motion and thus does not constrain the tissue. The sensitivity of the transducer is very high. An additional feature is the low cost of the transducer compared to strain-gauge devices.

scholarly journals Self-Calibration of an Industrial Robot Using a Novel Affordable 3D Measuring Device

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3380 ◽  
Author(s):  
Martin Gaudreault ◽  
Ahmed Joubair ◽  
Ilian Bonev
Keyword(s):  
Industrial Robot ◽  
Low Cost ◽  
Least Square Method ◽  
Calibration Method ◽  
Least Square ◽  
Geometrical Parameters ◽  
Robot Arm ◽  
Measuring Device ◽  
Self Calibration ◽  
Position Errors

This work shows the feasibility of calibrating an industrial robot arm through an automated procedure using a new, low-cost, wireless measuring device mounted on the robot’s flange. The device consists of three digital indicators that are fixed orthogonally to each other on an aluminum support. Each indicator has a measuring accuracy of 3 µm. The measuring instrument uses a kinematic coupling platform which allows for the definition of an accurate and repeatable tool center point (TCP). The idea behind the calibration method is for the robot to bring automatically this TCP to three precisely-known positions (the centers of three precision balls fixed with respect to the robot’s base) and with different orientations of the robot’s end-effector. The self-calibration method was tested on a small six-axis industrial robot, the ABB IRB 120 (Vasteras, Sweden). The robot was modeled by including all its geometrical parameters and the compliance of its joints. The parameters of the model were identified using linear regression with the least-square method. Finally, the performance of the calibration was validated with a laser tracker. This validation showed that the mean and the maximum absolute position errors were reduced from 2.628 mm and 6.282 mm to 0.208 mm and 0.482 mm, respectively.

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