Technical standards
Vietnamese Standard TCVN 8095-221:2010 (IEC 60050-221:1990)
Dec
NATIONAL STANDARD
TCVN 8095-221:2010
IEC 60050-221:1990
WITH AMENDMENT 1:1993
AMENDMENT 2:1999
AND AMENDMENT 3:2007
INTERNATIONAL ELECTROTECHNICAL VOCABULARY – PART 221: MAGNETIC MATERIALS AND COMPONENTS
International Electrotechnical Vocabulary – Part 221: Magnetic materials and components
I. Foreword
TCVN 8095-221:2010 replaces TCVN 3686-81 and TCVN 3676-81;
TCVN 8095-221:2010 is fully equivalent to IEC 60050-221:1990, amendment 1:1993, amendment 2:1999 and amendment 3:2007;
TCVN 8095-221:2010 was compiled by the National Technical Standards Committee TCVN/TC/E1 Electrical machines and apparatus, proposed by the General Department of Standards, Metrology and Quality, and announced by the Ministry of Science and Technology.
II. Introduction
TCVN 8095-221:2010 is part of the TCVN 8095 series of National Standards.
The TCVN 8095 (IEC 60050) series of National Standards currently includes the following standards:
TCVN 8095-151:2010 (IEC 60050-151:2001), International Electrotechnical Vocabulary – Part 151: Electrical and magnetic devices
TCVN 8095-212:2009 (IEC 60050-212:1990), International Electrotechnical Vocabulary – Part 212: Insulating solids, liquids and gases
TCVN 8095-221:2010 (IEC 60050-221:1990, amendment 1:1993, amendment 2:1999 and amendment 3:2007), International Electrotechnical Vocabulary – Part 221: Magnetic materials and components
TCVN 8095-300:2010 (IEC 60050-300:2001), International Electrotechnical Vocabulary – Chapter 300: Electrical and electronic measurements and measuring instruments
TCVN 8095-411:2010 (IEC 60050-411:1996 and amendment 1:2007). International Electrotechnical Vocabulary – Part 411: Rotating machinery
TCVN 8095-436:2009 (IEC 60050-436:1990), International Electrotechnical Vocabulary – Part 436: Power capacitors
TCVN 8095-446:2010 (IEC 60050-446:1983), International Electrotechnical Vocabulary – Part 446: Electrical relays
TCVN 8095-461:2009 (IEC 60050-461:2008), International Electrotechnical Vocabulary – Part 461: Electric cables
TCVN 8095-466:2009 (IEC 60050-466:1990), International Electrotechnical Vocabulary – Part 466: Overhead lines
TCVN 8095-471:2009 (IEC 60050-471:2007), International Electrotechnical Vocabulary – Part 471: Insulators
TCVN 8095-521:2009 (IEC 60050-521:2002), International Electrotechnical Vocabulary – Part 521: Semiconductor devices and integrated circuits
TCVN 8095-602:2010 (IEC 60050-602:1983), International Electrotechnical Vocabulary – Part 602: Generation, transmission and distribution of electricity – Generation
TCVN 8095-811:2010 (IEC 60050-811:1991), International Electrotechnical Vocabulary – Part 811: Electric traction
TCVN 8095-845:2009 (IEC 60050-845:1987), International Electrotechnical Vocabulary – Part 845: Lighting
III. INTERNATIONAL ELECTROTECHNICAL VOCABULARY – PART 221: MAGNETIC MATERIALS AND COMPONENTS
International Electrotechnical Vocabulary – Part 221: Magnetic materials and components
Section 221-01 – General terms
221-01-01
Magnetic field
The component of the electromagnetic field characterized by the magnetic field strength vector and the magnetic flux density vector .
221-01-02
Magnetic dipole (1)
An entity which, with respect to its magnetic field, can be represented by a differential current loop.
221-01-03
Magnetic dipole (2)
An entity which, with respect to its magnetic field at all points sufficiently remote from it, can be replaced by a planar current loop.
NOTE: A magnetic dipole may be any current loop, electric particles in orbital or spinning motion, or any combination thereof, e.g. a magnetized body.
221-01-04
Saturation magnetization
(symbol: Ms)
The maximum magnetization obtainable for a given substance at a given temperature.
221-01-05
Saturation magnetic polarization
(symbol: Js)
The maximum magnetic polarization obtainable for a given substance at a given temperature.
221-01-06
(Mass) density of saturation magnetization
Specific saturation magnetization
(symbol: d)
The saturation magnetization divided by the mass density.
221-01-07
Magnetic dipole moment
(symbol: J)
The vector quantity given by the volume integral of the magnetic polarization.
NOTE: The magnetic dipole moment is related to the magnetic area moment m by the formula J = mo m where m is defined in IEC 60050-121 and mo is the magnetic constant.
221-01-08
Magnetic anisotropy
The phenomenon in which the magnetic properties of a substance vary with different directions relative to a given frame of reference in that substance.
221-01-09
Induced magnetic anisotropy
Permanent or temporary magnetic anisotropy produced by external causes.
221-01-10
Magnetically anisotropic substance
A substance having magnetic anisotropy.
221-01-11
Magnetically isotropic substance
A substance having negligible magnetic anisotropy.
221-01-12
Magnetic texture
The structural arrangement of a polycrystalline magnetic material which gives rise to magnetic anisotropy.
221-01-13
Grain-oriented material
A material in which the magnetic texture is established by complete or partial orientation of the grains.
221-01-14
Hard magnetic material
A magnetic material having high coercivity.
NOTE: It is difficult to give a unique value of coercivity defining the boundary between hard and soft magnetic materials: it lies in the region of 1 kA/m to 10 kA/m.
221-01-15
Soft magnetic material
A magnetic material having low coercivity.
NOTE 1: It is difficult to give a unique value of coercivity defining the boundary between hard and soft magnetic materials: it lies in the region of 1 kA/m to 10 kA/m.
NOTE 2: Certain soft magnetic iron alloys, e.g. silicon-iron, used in electrical applications are commonly referred to as electrical steels.
221-01-16
Electrical steel
A soft magnetic steel intended for magnetic applications.
221-01-17
Ferrite
An oxidic material containing ferric ions as a major component and exhibiting ferromagnetism or ferrimagnetism.
NOTE 1: This term is usually restricted to material having a spinel structure.
NOTE 2: In metallurgy and mineralogy, the term ferrite often has a different meaning.
221-01-18
Semi-processed electrical steel
Electrical steel which has not received its final annealing process.
221-01-19
Magnetic hysteresis
In a ferromagnetic substance, the irreversible change of magnetic flux density or magnetization associated with a change of magnetic field strength and which is independent of the rate of change.
221-01-20
Bohr magneton
(symbol: mB)
A physical constant used to express the magnetic moment of the electron: its value is eh/4pm » (9.274078 ± 0.000036) x 10–24 Am2 where e is the elementary charge, h is the Planck constant, and m is the rest mass of the electron.
NOTE 1: The numerical value quoted is that adopted by the International Union of Pure and Applied Physics (IUPAP).
NOTE 2: The magnetic moment of a free electron due to its spin is approximately 1.001 mB.
Section 221-02 – Magnetization states
221-02-01
Thermally neutral state
Initial state
A magnetically neutral state achieved by cooling the material through its Curie point, in the absence of an external magnetic field.
221-02-02
Dynamically neutral state
A magnetically neutral state achieved by an external alternating magnetic field or, more usually, by an alternating-current reversed magnetic field whose peak value is progressively reduced from a value corresponding to saturation, to zero.
221-02-03
Statically demagnetized state
Statically neutral state
A magnetic state achieved by an external magnetic field which brings the magnetic flux density to a value such that on removal of this field the magnetic flux density returns to a value close to zero.
221-02-04
Cyclic magnetic condition
The condition of a magnetic material when the magnetic hysteresis loop is independent of the number of excursions of the uniform cycle to which the material is subjected.
221-02-05
Anhysteretic state
The state of a magnetic material achieved by a static magnetic field on which is superimposed an alternating magnetic field, the amplitude of which initially brings the material to magnetic saturation and is then reduced to zero.
221-02-06
Initial magnetization curve
The magnetization curve obtained when the material, initially in a magnetically neutral state, is subjected to a magnetic field of uniformly increasing strength from zero.
NOTE: The means of achieving the magnetically neutral state may be the thermal or the dynamic method; the method used should be stated.
221-02-07
Static magnetization curve
A magnetization curve obtained at a low rate of change of magnetic field strength such that the curve is unaffected by this rate of change.
221-02-08
Dynamic magnetization curve
A magnetization curve obtained when there is a sufficiently high rate of change of magnetic field strength to influence the shape of the curve.
221-02-09
B(H) curve
A magnetization curve expressing magnetic flux density as a function of magnetic field strength.
221-02-10
J(H) curve
A magnetization curve expressing magnetic polarization as a function of magnetic field strength.
221-02-11
M(H) curve
A magnetization curve expressing magnetization as a function of magnetic field strength.
221-02-12
B(H) loop
A closed loop expressing magnetic flux density as a function of magnetic field strength when the latter is periodic.
221-02-13
J(H) loop
A closed loop expressing magnetic polarization as a function of magnetic field strength when the latter is periodic.
221-02-14
M(H) loop
A closed loop expressing magnetization as a function of magnetic field strength when the latter is periodic.
221-02-15
Static B(H) loop
A B(H) loop obtained at a low rate of change of magnetic field strength such that the loop is unaffected by this rate of change.
221-02-16
Static J(H) loop
A J(H) loop obtained at a low rate of change of magnetic field strength such that the loop is unaffected by this rate of change.
221-02-17
Static M(H) loop
An M(H) loop obtained at a low rate of change of magnetic field strength such that the loop is unaffected by this rate of change.
221-02-18
Dynamic B(H) loop
A B(H) loop obtained at a sufficiently high rate of change of magnetic field strength to influence the shape of the loop.
221-02-19
Dynamic J(H) loop
A J(H) loop obtained at a sufficiently high rate of change of magnetic field strength to influence the shape of the loop.
221-02-20
Dynamic M(H) loop
An M(H) loop obtained at a sufficiently high rate of change of magnetic field strength to influence the shape of the loop.
221-02-21
Normal hysteresis loop
A hysteresis loop which is symmetrical about the origin of coordinates.
221-02-22
Normal B(H) loop
A B(H) loop which is symmetrical about the origin of coordinates.
221-02-23
Normal J(H) loop
A J(H) loop which is symmetrical about the origin of coordinates.
221-02-24
Normal M(H) loop
An M(H) loop which is symmetrical about the origin of coordinates.
221-02-25
Incremental hysteresis loop
An asymmetrical hysteresis loop obtained when there is a static magnetic field collinear with the time-varying magnetic field.
221-02-26
Incremental B(H) loop
An asymmetrical B(H) loop obtained when there is a static magnetic field collinear with the time-varying magnetic field.
221-02-27
Incremental J(H) loop
An asymmetrical J(H) loop obtained when there is a static magnetic field collinear with the time-varying magnetic field.
221-02-28
Incremental M(H) loop
An asymmetrical M(H) loop obtained when there is a static magnetic field collinear with the time-varying magnetic field.
221-02-29
Commutation curve
Normal magnetization curve
The locus of the tips of the normal hysteresis loops, when the peak value of the periodic magnetic field is varied.
221-02-30
Anhysteretic curve
A magnetization curve, every point of which represents an anhysteretic state.
221-02-31
Saturation hysteresis loop
A normal hysteresis loop for which the maximum value of the magnetic field strength brings the material to magnetic saturation.
221-02-32
Saturation B(H) loop
A normal B(H) loop for which the maximum value of the magnetic field strength brings the material to magnetic saturation.
221-02-33
Saturation J(H) loop
A normal J(H) loop for which the maximum value of the magnetic field strength brings the material to magnetic saturation.
221-02-34
Saturation M(H) loop
A normal M(H) loop for which the maximum value of the magnetic field strength brings the material to magnetic saturation.
221-02-35
Coercive field strength
The applied magnetic field strength required to bring the magnetic flux density, magnetic polarization or magnetization of a magnetic material to zero.
NOTE 1: In graphical representation, the coercive field strength is the value corresponding to the intersection with the H-axis of the magnetization curve (for magnetic flux density, magnetic polarization or magnetization).
NOTE 2: The coercive field strength may refer either to static or to dynamic magnetization. When not qualified, it is assumed to be static.
221-02-36
Coercivity
The value of the coercive field strength in the material when the magnetic flux density, magnetic polarization or magnetization is brought from a state of saturation by a uniform change of magnetic field.
NOTE: The parameter concerned should be stated, and the appropriate symbol used as follows: HcR for coercivity related to magnetic flux density, for coercivity related to polarization, for coercivity related to magnetization. The first two symbols replace the symbols BHC and jHc.
221-02-37
Cyclic coercivity
The value of the coercive field strength in the material when the magnetic flux density, magnetic polarization or magnetization is reversed in magnitude corresponding to the saturation hysteresis loop.
NOTE: The parameter concerned should be stated, and the appropriate symbol used as follows: HlcB for cyclic coercivity related to magnetic flux density, HlcJ for cyclic coercivity related to polarization, HlcM for cyclic coercivity related to magnetization. The first two symbols replace the symbols BHlc and JHlc.
221-02-38
Remanent magnetic flux density
The value of the magnetic flux density remaining in a magnetized body when, in the absence of a self-demagnetizing field, the applied magnetic field strength is brought to zero.
NOTE: When the initial state is that of magnetic saturation, the remanent magnetic flux density is termed “remanence” (see IEV Part 121).
221-02-39
Remanent magnetic polarization
The value of the magnetic polarization remaining in a magnetized body when, in the absence of a self-demagnetizing field, the applied magnetic field strength is brought to zero.
221-02-40
Remanent magnetization
The value of the magnetization remaining in a magnetized body when, in the absence of a self-demagnetizing field, the applied magnetic field strength is brought to zero.
221-02-41
Spontaneous magnetization
The magnetization caused by the alignment of atomic magnetic moments in the absence of an applied external magnetic field.
221-02-42
Magnetic annealing
The heat treatment of a magnetic material in the presence of an applied magnetic field in order to achieve a desired magnetic texture.
221-02-43
Magnetic conditioning
The treatment of a magnetic material or magnetic core to remove its previous magnetic history and to bring it to a reproducible magnetic state.
221-02-44
Domain wall
A boundary region, several lattice elements thick, between adjacent Weiss domains, within which the direction of the magnetic moment changes gradually from that of one domain to that of the next.
221-02-45
Bloch wall
A domain wall in which the component of the magnetic moment perpendicular to the plane of the wall is essentially constant within and on both sides of the wall.
NOTE: See note to term “Néel wall”.
221-02-46
Néel wall
A domain wall in which the direction of the magnetic moment changes as it passes through the wall and remains in the plane perpendicular to the plane of the wall.
NOTE: Néel walls are usually formed only in thin magnetic films below a critical thickness; in thicker films and in bulk materials, the formation of Bloch walls is preferred.
221-02-47
Barkhausen effect
Barkhausen jump
A discontinuous change in magnetic flux density in a magnetic material when the applied field strength is changed continuously.
NOTE: In an electric circuit, the Barkhausen effect will give rise to noise called “Barkhausen noise”.
221-02-48
(Magnetic) variability
The change in the properties of a magnetic material or magnetic circuit with time or working conditions.
221-02-63
Temperature coefficient of saturation magnetization
(symbol: aMs)
The ratio of the relative change of saturation magnetization due to a change in temperature, to that change in temperature.
aMs =
where MsQ and Msref are the saturation magnetizations at temperatures Q and Qref respectively.
221-02-64
Temperature coefficient of saturation magnetic polarization
(symbol: aJs)
The ratio of the relative change of saturation magnetic polarization due to a change in temperature, to that change in temperature.
where JsQ and Jsref are the saturation magnetic polarizations at temperatures Q and Qref respectively.
221-02-49
Temperature factor of permeability
The temperature coefficient of permeability divided by the permeability at temperature q.
or
where mq and mref differ negligibly.
NOTE: The temperature factor of permeability is a material property which permits the calculation of the temperature coefficient of effective permeability ame by multiplying mF by me:
ame = aF . me
221-02-50
Temperature coefficient of permeability
(symbol: am)
The fractional change of permeability due to a change of temperature divided by that change of temperature:
where mo and mref are the permeabilities at temperatures q and qref respectively.
221-02-51
Temperature coefficient of effective permeability
(symbol: ame)
The fractional change of effective permeability due to a change of temperature divided by that change of temperature:
where (me)q and (me)ref are the effective permeabilities at temperatures q and qref respectively.
221-02-52
Temperature coefficient of inductance
(symbol: aL)
The fractional change of inductance due to a change of temperature divided by that change of temperature:
where Lq and Lref are the inductances at temperatures q and qref respectively.
221-02-53
Magnetic ageing
The irreversible change in magnetic properties of a material with time, this change arising from changes in the material structure.
NOTE: Appropriate heat treatment may accelerate the change or restore the initial state.
221-02-54
Disaccommodation (of permeability)
(symbol: D)
The fractional decrease of permeability of a magnetic material measured at constant temperature at the beginning and end of a given time interval:
where m1 and m2 are the values of permeability at the beginning and end of the given time interval respectively.
221-02-55
Disaccommodation coefficient (of permeability)
(symbol: d)
The disaccommodation of permeability after magnetic conditioning divided by the logarithm (base 10) of the ratio of the time interval from the cessation of conditioning to the second measurement, and the time interval from the cessation of conditioning to the first measurement:
where D is the disaccommodation measured in the time interval t1 to t2 after magnetic conditioning.
221-02-56
Disaccommodation factor (of permeability)
(symbol: DF)
The disaccommodation coefficient divided by the relative permeability measured at the first measurement:
221-02-57
Magnetic relaxation
The process of achieving equilibrium in a magnetic system after a disturbance, which takes place over a finite time due to the dynamics of atomic or sub-atomic particles.
NOTE: When unspecified, this term usually relates to short term processes having time constants of the order of microseconds.
221-02-58
Magnetic after-effect
Magnetic relaxation having time constants in the range of seconds to many days.
221-02-59
Magnetic viscosity
The magnetic after-effect caused by a change in the applied static magnetic field.
221-02-60
Instability (of permeability)
(symbol: S)
The fractional change of permeability caused by a specified disturbance:
where m2 and m1 are the permeabilities immediately before and at a specified time after the application of the disturbance respectively.
221-02-61
Instability factor (of permeability)
(symbol: SF)
The instability of permeability S divided by the relative permeability m1, measured immediately before the application of the disturbance:
221-02-61
Knee field strength (of a hard magnetic material)
(symbol: Hk)
The negative value of magnetic field strength at which the magnetic polarization of a hard magnetic material is brought from saturation to 90 % of its remanent magnetic polarization value by a uniform change of magnetic field.
SECTION 221-03 – PERMEABILITY AND LOSSES
221-03-01
Relative permeability
(symbol: mT)
The ratio of the absolute permeability of a substance to the magnetic constant.
221-03-02
Tensor permeability
(symbol: m)
A tensor quantity giving the relationship between the space vectors representing the magnetic flux density and the magnetic field strength inside a material:
221-03-03
Polder tensor permeability
Tensor permeability for a statically-saturated medium
(symbol: )
The tensor permeability of a material saturated by a static magnetic field collinear with the time-varying magnetic field, with the direction of the static field defining the Z-axis:
where mr and Kr are complex permeabilities.
221-03-04
Scalar permeability for circularly polarized fields
(symbol: m+ , m–)
In a material saturated by a static magnetic field, the complex permeability when subjected to an electromagnetic wave having its field component circularly polarized in the plane perpendicular to the static magnetic field strength:
m+ = mr + Kr
m– = mr – Kr
where mr and Kr, are the components of the Polder tensor permeability.
NOTE: The suffix of m corresponds to the mathematical notation; m+ is used when the field rotates counter-clockwise as a function of time when viewed in the direction of the applied static field; m– is used for the reverse direction of rotation.
221-03-05
Effective scalar permeability
In a material saturated by a static magnetic field, the complex permeability when subjected to an electromagnetic wave in a plane propagating in a direction, and having its field component perpendicular to, the field strength:
where mr and Kr are the components of the Polder tensor permeability.
221-03-06
Complex permeability
(symbol: m)
The complex quotient of magnetic flux density and magnetic field strength in a material when one of these quantities varies sinusoidally with time at the same frequency, i.e. the fundamental component. The vectors representing magnetic flux density and magnetic field strength are assumed to be collinear:
m = m/ – jm//
where m/ and m// are the real and imaginary components respectively of the complex permeability.
NOTE: In general, the permeabilities defined in this document can be expressed as complex permeabilities. Where these are represented by symbols which do not indicate that they are components of a complex number, it is assumed that they are the real parts.
221-03-07
Amplitude permeability
(symbol: ma)
The relative permeability obtained from the peak value of magnetic flux density and the peak value of the applied magnetic field strength, at a specified amplitude of one of them, when the field strength varies periodically with time and has zero mean value, and the material is initially in a specified neutral state.
NOTE 1: Two amplitude permeabilities are in common use:
- i) a permeability in which the peak values apply to the actual waveforms,
- ii) a permeability in which the peak values apply to the fundamental components, in which case it is necessary to distinguish which component is that of the waveform, if both are sinusoidal.
NOTE 2: In the limit, and may be static values provided that the material is in a cyclic magnetic condition.
221-03-08
Rms amplitude permeability
(symbol: ma,eff, ma,rms)
The relative permeability obtained from the peak magnetic flux density divided by and the rms value of the applied magnetic field strength at a specified peak value of magnetic flux density, when the magnetic flux density varies sinusoidally with time with zero mean value and the material is initially in a specified neutral state.
221-03-09
Initial permeability
(symbol: mi)
The limiting value of the amplitude permeability as the magnetic field strength tends to zero:
221-03-10
Maximum permeability
(symbol: mmax)
The maximum value of the amplitude permeability observed when the amplitude of the magnetic field strength is varied.
221-03-11
Pulse permeability
(symbol: mP)
The relative permeability obtained from the total change of magnetic flux density and the corresponding change of magnetic field strength when both quantities vary with any waveform between two specified limits:
NOTE 1: The value of pulse permeability is very dependent on the limits of magnetic flux density or magnetic field strength excursion; these limits are not necessarily symmetrical about zero.
NOTE 2: Pulse permeability usually relates to the special case of rectangular voltage pulses being applied to an exciting winding, the flux waveform thus having an approximately triangular shape provided that saturation is not reached.
221-03-12
Permeability rise factor
(symbol: dH)
The change of amplitude permeability between two specified peak values of sinusoidal magnetic field strength divided by the difference in the peak values of the field strength:
221-03-13
Incremental permeability
(symbol: mD)
The relative permeability obtained from the peak-to-peak value of magnetic flux density and the peak-to-peak value of the applied magnetic field strength, at a specified amplitude of one of them, when the field strength varies periodically with time about a specified static value.
NOTE 1: The notes of the definition of amplitude permeability apply to this definition.
NOTE 2: The incremental permeability depends on the way in which the magnetic material is brought to its static field strength value. This definition implies that the alternating and static fields are collinear: if they are not, the permeability becomes a tensor quantity.
221-03-14
Reversible permeability
(symbol:mrev)
The limiting value of the incremental permeability as the alternating field strength tends to zero:
221-03-15
Differential permeability
(symbol: mdif)
The relative permeability corresponding to the slope at a given point on a magnetization curve of magnetic flux density:
221-03-16
Recoil permeability
(symbol: mrec)
The permeability corresponding to the slope of a recoil line.
221-03-17
Effective permeability
(symbol: me)
For a magnetic circuit composed of different insulating materials or non-homogeneous materials or both, the permeability of a hypothetical homogeneous material which, when used to construct a circuit of identical dimensions, would produce the same reluctance.
NOTE 1: In the case of different materials connected in series along the magnetic path and where the permeability may be considered constant within any cross-section, the following formula applies:
where l is the length, measured along the magnetic path, of each part of the core having uniform cross-section A and uniform permeability k.
NOTE 2: Effective permeability is used particularly in relation to cores having (air) gaps and is usually restricted to cases where the leakage flux is relatively small.
221-03-18
Apparent permeability
(symbol: mapp)
The ratio of the inductance, L, of a coil when assembled in a specified position on a given core, to the inductance, L’, of that coil measured without the core:
221-03-19
Initial susceptibility
(symbol: Ki)
The limiting value of magnetic susceptibility, as both the magnetic field strength and the magnetic flux density tend to zero.
221-03-20
Inductance factor
(symbol: AL)
The inductance of a coil of specified shape, placed on a given core in a specified position, divided by the square of the number of turns.
AL = L/N2
where L is the inductance of the coil placed on the core and N is the number of turns on the coil.
NOTE 1: The inductance factor is closely related to the permeance A; the permeance relates to the reluctance of the core whereas the inductance factor relates to a coil on the core.
NOTE 2: In principle, the inductance factor can correspond to any of the forms of permeability defined in the IEV, e.g. amplitude permeability, but in the absence of any other stipulation it should be assumed that the inductance factor corresponds to the effective permeability at small field strengths.
NOTE 3: The concept “turns factor” (a) was formerly used. This was defined as: the number of turns which a coil of specified shape, placed on a given core in a specified position, would require to achieve unit inductance (usually one millihenry):
221-03-21
(Mass) density of total loss
Specific total loss
In a uniformly magnetized material, the total energy absorbed in a given mass divided by that mass.
221-03-22
(Volume) density of total loss
In a uniformly magnetized material, the total energy absorbed in a given volume divided by that volume.
221-03-23
Eddy current loss
The energy absorbed by a material due to eddy currents.
221-03-24
Hysteresis loss
The energy absorbed by a material due to magnetic hysteresis.
221-03-25
Rotational hysteresis loss
The energy absorbed by a material due to magnetic hysteresis when the material is subjected to a magnetic field whose direction rotates in a plane.
221-03-41
Rotational energy loss
The total energy absorbed by a material when it is subjected to a magnetic field whose direction rotates in a plane.
221-03-26
Residual loss
The difference between the total loss and the sum of the eddy current loss and the hysteresis loss.
NOTE: In a magnetic material, the division of the losses into eddy current, hysteresis and residual losses is based on assumptions which must be fully evaluated. The definitions given here represent accepted technological usage.
221-03-27
Gyromagnetic resonance loss
The energy absorbed by a material due to gyromagnetic resonance.
221-03-28
(Magnetic) loss angle
(symbol: dm)
The phase displacement between the fundamental components of magnetic flux density and magnetic field strength.
NOTE 1: Where the phase displacement can be associated with eddy current loss, hysteresis loss or residual loss, the loss angle may be designated dF for eddy current loss, dh, for hysteresis loss and dr, for residual loss.
NOTE 2: The tangent of the loss angle is often used to express the loss in a magnetic material:
tan dm =
where ml and mll are the real and imaginary components respectively of the complex permeability (symbol: m)
221-03-29
(Magnetic) quality factor
(symbol: Qm)
The reciprocal of the tangent of the magnetic loss angle.
221-03-30
Magnetic loss resistance
In an equivalent circuit representing a magnetic circuit with a winding or other coupling device, the series or parallel resistance in which the power dissipated is equal to the magnetic loss in the circuit.
221-03-31
(Magnetic) loss factor
(symbol )
The tangent of the magnetic loss angle divided by the relative permeability:
where ml and mll are the real and imaginary components respectively of the complex permeability.
221-03-32
Rayleigh region
In the graphical representation of the relationship between magnetic flux density and magnetic field strength in a material, the region near the origin in which the magnetic flux density can be described by a quadratic function of the field strength:
where B is the magnetic flux density
m0 is the magnetic constant
mi is the initial permeability
H is the magnetic field strength
is the peak value of H
and v is the Rayleigh hysteresis coefficient.
221-03-33
Hysteresis material factor
(symbol: hB)
The magnetic loss factor due to hysteresis divided by the peak value of the magnetic flux density, when the magnetic material is operating in the Rayleigh region:
221-03-34
Hysteresis core constant
(symbol: hi)
In a magnetic core operating in the Rayleigh region, the tangent of the magnetic loss angle due to hysteresis divided by the product of the peak current in, and the square root of the inductance L of, the winding:
NOTE: The relationship between the hysteresis material constant hB and the hysteresis core constant is:
where me is the effective permeability and Ve is the effective volume.
221-03-35
Jordan diagram
A graph showing the tangent of the magnetic loss angle, or some closely related quantity, as a function of magnetic field strength in the Rayleigh region, with frequency as a parameter.
221-03-36
(Mass) density of apparent power
Specific apparent power
The apparent power transmitted in a given mass divided by that mass, in a uniformly magnetized material.
221-03-37
(Volume) density of apparent power
The apparent power transmitted in a given volume divided by that volume, in a uniformly magnetized material.
221-03-38
Anisotropy loss factor
(symbol: T)
In electrical steel, the ratio of the difference between the magnetic losses P90 measured perpendicular to the rolling direction and P0 measured parallel to the rolling direction, expressed as a percentage:
NOTE: The measurements P90 and P0 are made under identical conditions.
221-03-39
Anisotropy loss factor (at a given loss angle)
(symbol: TL)
In electrical steel, the ratio of the difference between the magnetic loss Pa measured at an angle a to the rolling direction and the magnetic loss P0 measured along the rolling direction, to P0, expressed as a percentage:
NOTE 1: The measurements Pa and P0 are made under identical conditions.
NOTE 2: The anisotropy loss factor at a given angle differs from the anisotropy loss factor T both in concept and in value (221-03-38).
221-03-40
Anisotropy magnetic field strength loss
(symbol: TH)
In electrical steel, the ratio of the difference between the peak value of the magnetic field strength Ha measured at an angle a to the rolling direction and the peak value of the magnetic field strength , measured along the rolling direction, to H0, at a specified peak value of magnetic flux density, expressed as a percentage:
NOTE: The measurements and are made under identical conditions.
221-03-41
(Magnetic) total harmonic distortion
Voltage waveform distortion due to the non-linear relationship between magnetic flux density and magnetic field strength in a magnetic core and expressed in decibels by the formula:
THD = 20lg(Vm/Vf)dB
where
Vn is the amplitude of the nth harmonic component of the waveform and Vf is the amplitude of the fundamental component.
221-03-42
(Magnetic) total harmonic distortion factor
A mathematical expression used for evaluating the properties of magnetic materials and expressed in decibels by the formula:
where
, Vn is the amplitude of the nth harmonic and V¦ is the amplitude of the fundamental component,
mea is the amplitude permeability,
CCF is the circuit correction factor.
NOTE 1: In practice, is an abbreviation of the circuit correction factor and is taken as approximately the third harmonic, this factor being valid for measurement without d.c. bias.
L1 is the primary inductance. Rs is the total source resistance (50W).
NOTE 2: THDF is sometimes expressed in decibels.
SECTION 221-04 – MAGNETIC BODIES
221-04-01
Magnetization
The production of magnetization in a body.
221-04-02
Demagnetization
The reduction of the magnetic flux density of a magnetic material along a demagnetization curve.
NOTE: This definition applies mainly in permanent magnet technology.
221-04-03
Neutralization
Demagnetization
To bring a magnetic material to a magnetically neutral state.
NOTE: Neutralization may be achieved by thermal or dynamic methods.
221-04-04
Demagnetizing factor
(symbol: N)
For a uniformly magnetized body, the ratio of the self-demagnetizing field strength to the magnetization.
NOTE 1: If the magnetization is non-uniform, an average value may be assigned as the demagnetizing factor but the conditions must be specified.
NOTE 2: In permanent magnet technology, the demagnetizing factor is sometimes used to express the slope of the load line.
221-04-05
BH product
The product of the magnetic flux density and the magnetic field strength of a permanent magnet at any point of the demagnetization curve.
NOTE 1: The maximum value obtained on the demagnetization curve is termed (BH)max.
NOTE 2: The BH product is equal to twice the energy stored in the external magnetic field of the magnet per volume of the magnet.
221-04-06
Fullness factor (related to flux density)
(symbol: g)
The ratio of the BH product of a permanent magnet to the product of the remanence Br and the coercivity related to magnetic flux density BcB.
221-04-07
Fullness factor (related to polarization)
(symbol: gl)
The maximum value of the product of magnetic polarization and magnetic field strength divided by the product of the remanence Br, and the coercivity related to polarization Hcj
221-04-08
Recoil state
The state of a permanent magnet when the internal magnetic field is reduced, for example by a reduction in the reluctance of the circuit or by a reduction in an external demagnetizing field.
221-04-09
Recoil line
Recoil curve
Recoil loop
The hysteresis loop or part of that loop which a permanent magnet traverses during the recoil state.
NOTE: In practice, the recoil line is generally indistinguishable from a straight line.
221-04-10
Working point
In a permanent magnet material forming part of a given magnetic circuit, the point on the demagnetization curve or recoil line whose coordinates are the working magnetic flux density and magnetic field strength.
221-04-11
Load line
The locus of the working points of a permanent magnet material forming part of a given magnetic circuit when the magnitude of the magnetization is varied.
221-04-12
Leakage factor
The ratio of the total magnetic flux to the useful magnetic flux of a magnetic circuit.
221-04-13
Air-gap
A gap between magnetic parts of a magnetic circuit, which is traversed by magnetic flux lines and which is small compared with the total magnetic path length.
221-04-14
Magnetic axis
The axis of the magnetic moment of a magnet.
221-04-15
Pole face
That surface of a magnet through which the useful magnetic flux passes.
221-04-16
North pole (of a magnet)
That pole of a magnet from which the external magnetic flux is conventionally directed.
NOTE: The north pole of a magnet is attracted by the earth’s magnetic pole nearest to the earth’s geographic North Pole.
221-04-17
North pole face
That pole face of a magnet from which the external magnetic flux is conventionally directed.
221-04-18
South pole (of a magnet)
That pole of a magnet into which the external magnetic flux is conventionally directed.
NOTE: The south pole of a magnet is attracted by the earth’s magnetic pole nearest to the earth’s geographic South Pole.
221-04-19
South pole face
That pole face of a magnet into which the external magnetic flux is conventionally directed.
221-04-20
Polarity
The designation of the poles or pole faces of a magnet as north poles or north pole faces and as south poles or south pole faces.
221-04-21
Neutral line
The locus of points on the surface of a magnet at which the normal component of the magnetic flux density is zero.
NOTE. The neutral line divides the surface into regions of opposite polarity.
221-04-22
Magnetic attraction
The force of attraction between two magnetic poles of opposite polarity.
NOTE: In the case of two parallel pole faces of equal area separated by a very small air-gap, the magnetic attraction is given by:
integrated over the area A of one of the pole faces.
221-04-23
Pole piece
A piece of soft magnetic material attached to a magnetic pole or yoke of a magnet to direct or concentrate the magnetic flux.
221-04-24
Magnetic core
- That part of a magnetic circuit which is composed of magnetic material.
- That part of a magnetic circuit which is designed to be placed inside a winding in a fixed position relative to it.
221-04-25
Laminated magnetic core
A core composed of sheets of soft magnetic material or pieces cut from such material, arranged in parallel formation, and having sufficient inter-laminar resistance for the application.
221-04-26
Pressed powder magnetic core
A core consisting of a mass of magnetic powder particles having sufficient inter-particle contact resistance for the application.
221-04-27
Wound tape magnetic core
A core consisting of one or more strips of soft magnetic material, wound one upon the other, and having sufficient inter-laminar resistance for the application.
221-04-28
Lamination factor (of a laminated or wound tape core)
Stacking factor (of a laminated or wound tape core)
The ratio of the metallic cross-section to the total cross-section of the laminations.
221-04-29
Core factor C1
Core inductance parameter
(symbol:C1)
For a magnetic core of given shape, divided into a series of longitudinal elements of constant cross-section, the sum of the quotients of the length / of the elements measured along an assumed mean magnetic path, and the corresponding cross-sectional area A.
221-04-30
Core factor C2
Core hysteresis parameter
(symbol: C2)
For a magnetic core of given shape, divided into a series of longitudinal elements of constant cross-section, the sum of the quotients of the length l of the elements measured along an assumed mean magnetic path, and the square of the corresponding cross-sectional area A.
221-04-31
Effective dimensions (of a magnetic circuit)
For a magnetic core operating in the Rayleigh region, and of given shape and material properties, the magnetic path length, cross-sectional area and volume of a hypothetical toroidal core of the same material properties and of uniform and radially thin cross-section which would be magnetically equivalent to the given core.
NOTE 1:
The effective dimensions are:
Effective cross-sectional area
effective magnetic path length,
effective volume,
where C1 and C2 are the appropriate core factors, so that:
NOTE 2: These formulae may also be applied to a magnetic circuit operating outside the Rayleigh region provided that the magnetization can be considered as uniform, e.g. as in an Epstein frame.
221-04-32
Yoke
That part of a magnetic circuit whose principal function is to provide a low reluctance path for the magnetic flux.
221-04-33
Active mass
Effective mass
In a magnetic body, the mass which is considered to be effectively magnetized under given conditions.
221-04-34
Active mass factor
Effective mass factor
The ratio of the active mass to the total mass of a magnetic body.
221-04-35
Interleaved joint
A joint between two laminations of material in the form of flat strips, lying parallel in a common plane and meeting to form a right-angle, the strips being interleaved throughout their length.
221-04-36
Epstein frame
Epstein test frame
In apparatus used for measuring the magnetic properties of samples of magnetic sheet material, a component in which the sample is in the form of layers of flat rectangular strips arranged in a closed magnetic circuit around the sides of a frame, each side having test windings surrounding the sample.
221-04-37
Permeameter
Apparatus used to determine the relationship between magnetic flux density and magnetic field strength in a sample of magnetic material which may be in the form of flat strips, flat rectangular bars or straight bars and which is placed at the centre of a coil former carrying the test winding of the apparatus, the ends of the sample projecting outside the coil former so that the magnetic circuit may be completed by one or more yokes.
221-04-38
Search coil
A coil or loop used to detect or measure a magnetic field.
221-04-39
Effective area (of a search coil)
That area which, when multiplied by the number of turns and by the rate of change of magnetic flux density, gives the induced voltage in the search coil when it is situated in a uniform time-varying magnetic field, the direction of the field being parallel to the axis of the coil.
221-04-40
Area turns (of a search coil)
The product of the effective area of a search coil and its number of turns.
SECTION 221-05 – NON-RECIPROCAL ELECTROMAGNETIC COMPONENTS
221-05-01
Gyromagnetic effect
A phenomenon whereby the magnetization of a material or medium situated in a static magnetic field, on being disturbed, decays back to equilibrium by a damped precessional motion about the direction of that field.
221-05-02
Faraday effect
Faraday rotation
The phenomenon of rotation about the direction of propagation of the magnetic flux density vector of a linearly polarized electromagnetic wave on passing through a gyromagnetic medium situated in a static magnetic field having a component along the direction of propagation.
221-05-03
Gyromagnetic ratio (of an electron)
(symbol: g)
For an electron in a gyromagnetic substance, the quotient of the magnetic area moment due to spin, and its spin angular momentum.
NOTE 1: The angular precession frequency w of the electron is related to the applied magnetic field H by the following formula:
w = gm0H
where m0 is the magnetic constant and g is the gyromagnetic ratio.
NOTE 2: For a free electron, the gyromagnetic ratio is approximately 176×109 Ckg–1.
221-05-04
Gyromagnetic resonance
Resonance associated with the gyromagnetic effect, at which the frequency of the applied periodic magnetic disturbance coincides with that of the precession, causing strong coupling between the disturbance and that precession.
221-05-05
Gyromagnetic material
Gyromagnetic medium
A material or medium capable of exhibiting the gyromagnetic effect.
NOTE: The electromagnetic properties of a gyromagnetic material or medium exhibit an anisotropy described by a tensor permeability.
221-05-06
Gyromagnetic device
A device using a gyromagnetic material or medium.
221-05-07
Gyromagnetic resonator
A piece of gyromagnetic material designed to exhibit gyromagnetic resonance.
221-05-08
Non-reciprocal phase-shifter
A two-port device whose propagation medium produces a different phase-shift for the two different directions of propagation.
NOTE: The amount of phase-shift may be varied continuously (analogue phase-shift) or in steps (digital phase-shift).
221-05-09
Non-reciprocal polarization rotator
Non-reciprocal wave rotator
A waveguide structure, usually of circular cross-section, whose propagation medium causes the direction of polarization, i.e. the direction of the electric field vector, of a linearly polarized wave to rotate clockwise in one direction of propagation and counter-clockwise in the other direction, in both cases viewed in the direction of propagation.
221-05-10
Microwave gyrator
A non-reciprocal phase-shifter operating at microwave frequencies and having a differential phase-shift of essentially A radians.
221-05-11
Circulator
A passive device having three or more ports in which energy entering the ports is transmitted to the next port in a given sequence.
NOTE: By reversing the polarizing field, this sequence is reversed. This property may be used to switch electromagnetic energy.
221-05-12
Phase-shift circulator
A circulator containing at least one non-reciprocal phase-shifter.
221-05-13
(Wave) rotation circulator
A circulator containing at least one non-reciprocal polarization rotator.
221-05-14
Junction circulator
A circulator providing a junction between transmission lines.
NOTE: Junction circulators may be formed in several different ways characterized by the symmetry of that junction. For defining these types of circulator, the term “junction” is often omitted and other notations used instead. For example the terms “Y-circulator” and “T-circulator”, where the capital letters are used to describe the types of junction used.
In the case of waveguide junction circulators, it may be necessary to add a qualifying phrase e.g. “H-plane Y-circulator”. These associated phrases should be consistent with waveguide terminology (see IEV Part 726).
221-05-15
Lumped-element circulator
A circulator in which the ports are internally connected by a network of lumped impedance elements.
221-05-16
(Microwave) isolator
Unidirectional attenuator
A passive two-port device operating at microwave frequencies and having a much greater attenuation in one direction of propagation than in the other.
221-05-17
(Wave) rotation isolator
An isolator comprising at least one non-reciprocal polarization.
221-05-18
Resonance (absorption) isolator
A microwave isolator whose operation depends on resonance absorption in a gyromagnetic material or medium.
221-05-19
Field-displacement isolator
A microwave isolator whose operation depends on field displacement caused by a gyromagnetic material or medium.
NOTE: Field displacement is defined in IEV Part 726.
221-05-20
Lumped-element isolator
A microwave isolator in which the two ports are internally connected by a network of lumped impedance components.
221-05-21
Gyromagnetic filter
A filter containing at least one gyromagnetic resonator.
221-05-22
Gyromagnetic power limiter
A power limiter containing at least one gyromagnetic device, whose operation depends on non-linear saturation effects in that device.
221-05-23
Differential phase-shift (of a non-reciprocal phase-shifter)
The difference in phase-shift between the two directions of propagation of a non-reciprocal phase-shifter.
221-05-24
Forward direction (of an isolator or circulator)
That direction of the propagation path between two ports of a microwave isolator or circulator in which the energy propagates with very much less attenuation than in the reverse direction (backward direction).
221-05-25
Backward direction (of an isolator or circulator)
That direction of the propagation path between two ports of a microwave isolator or circulator in which the energy propagates with very much greater attenuation than in the reverse direction (forward direction).
221-05-26
Forward loss
The insertion loss of a microwave isolator or circulator in the forward direction.
221-05-27
Backward loss
The insertion loss of a microwave isolator or circulator in the backward direction.
221-05-28
Cross-coupling (of a circulator)
In a circulator having four or more ports, the attenuation between an input port and any other port which is not adjacent to that input port in the sequence of transmission.
NOTE: Cross-coupling should not be confused with backward loss which occurs between adjacent ports.
221-05-29
Isolation ratio
The ratio of the backward loss to the forward loss, both expressed in decibels, along a transmission path in a microwave isolator or circulator.
IV. Occupational safety solutions for businesses
1. Occupational safety training
An Toan Nam Viet is a reputable and high-quality center specializing in occupational safety training in Vietnam today. With occupational safety training sessions held continuously at factories, plants, or construction sites across the country (63 provinces in Vietnam).
REGISTER FOR OCCUPATIONAL SAFETY TRAINING SERVICE
Occupational safety training license
- An Toan Nam Viet has been inspected and certified by the Department of Safety of the Ministry of Labor – Invalids and Social Affairs as eligible to conduct occupational safety and health training. This further strengthens our occupational safety training capabilities.
Materials and Lectures
- Before occupational safety training materials are used in OHS training courses, they are reviewed and approved to ensure that the lectures are always accurate in knowledge and effective when applied.
- The teaching methods of the instructors are standardized according to An Toan Nam Viet’s teaching standards, which is a method researched and refined by experts in occupational safety and health training during the teaching process to bring the highest knowledge acquisition efficiency for trainees.
Facilities
- Controlling factors in the classroom that affect the training process will increase teaching performance and the trainee’s knowledge acquisition efficiency.
- The facilities supporting the training course always provide spacious classrooms that meet standards for area, lighting, training equipment …etc…
Our safety training center is proud to be a reputable and professional provider of occupational safety training services with the following advantages:
- Competitive training costs while still ensuring training quality.
- Flexible training schedules to fit the production situation of companies and businesses.
- Fast and legally compliant procedures for issuing occupational safety training certificates.
- Training instructors are individuals with many years of experience in the field.
- Classrooms are controlled for factors affecting the training process, increasing teaching performance and trainee’s knowledge acquisition efficiency.
- Lectures are tailored to occupational safety work at businesses.
- An Toan Nam Viet works diligently and professionally to support customers accurately and quickly.
2. Workplace environment monitoring
Nam Viet’s Workplace Environment Monitoring Center is a professional unit specializing in monitoring and measuring the quality of the working environment across all provinces in Vietnam. With a team of experienced monitoring specialists, the center uses modern measuring equipment, ensuring accuracy and reliability.
In addition to providing monitoring services, the center also supports clients in planning, handling, and tracking workplace environment issues. With the motto “the customer is the center,” the center focuses on customer satisfaction, meets all customer needs, and commits to providing the best solutions for businesses.
REGISTER FOR WORKPLACE ENVIRONMENT MONITORING SERVICE
With investment in engineering, technology, and human resources, Nam Viet’s monitoring center has and is becoming one of the reputable units in the field of workplace environment monitoring in Ho Chi Minh City with the following objectives:
- We always value our brand reputation and the quality of our products and services.
- We provide customers with the best and most suitable things possible.
- Along with a team of experienced Masters and Engineers with expertise and a desire to protect the environment and benefit businesses.
- Coming to the Nam Viet Environmental Monitoring team, your company will receive professional service from experts in the monitoring field. At the same time, you will get the best cost incentives.
The process of conducting workplace environment monitoring at Nam Viet includes the following basic steps:
- Before conducting workplace environment monitoring, our company always ensures that machinery and equipment for monitoring are calibrated and verified in accordance with legal regulations.
- Correctly and fully implement the workplace environment monitoring process as committed to the Department of Health.
- Truthfully report the workplace environment monitoring results to the employer.
- In case the workplace environment monitoring results are not safe for employees, Nam Viet company will support proposing remedial solutions, and the labor establishment will implement the following:
- Implement measures to improve working conditions to minimize the impact of harmful factors and prevent occupational diseases.
- Organize health checks to detect occupational diseases and work-related illnesses early for employees in positions with unsafe working environments.
- Provide in-kind allowances for employees according to labor laws.
