ASTM A889/A889M-03

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Designation:A 889/A889M–03
Standard Test Method for
Alternating-Current Magnetic Properties of Materials at Low
Magnetic Flux Density Using the Voltmeter-Ammeter-
1
Wattmeter-Varmeter Method and 25-cm Epstein Frame
This standard is issued under the fixed designationA889/A 889M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This test method shall be used in conjunction with
Practice A 34/A 34M.
1.1 This test method covers tests for the magnetic properties
1.7 Explanationofterms,symbols,anddefinitionsusedmay
ofbasicflat-rolledmagneticmaterialsatpowerfrequencies(25
befoundinthevarioussectionsofthistestmethod.Theofficial
to 400 Hz) using a 25-cm Epstein test frame and the 25-cm
list of definitions and symbols may be found in Terminology
double-lap-jointed core.
A 340.
1.2 The magnetic properties of materials are determined
1.8 The values and equations stated in customary (cgs-emu
from measurements on Epstein core specimens with the core
and inch-pound) or SI units are to be regarded separately as
andtestcoilstreatedasthoughtheyconstitutedaseries-parallel
standard. Within this standard, SI units are shown in brackets.
equivalent circuit (Fig.A1.1) for the fundamental frequency of
The values stated in each system may not be exact equivalents;
excitation where the apparent parallel inductance, L , and
1
therefore,eachsystemshallbeusedindependentlyoftheother.
resistance, R , are attributable to the test specimen.
1
Combining values from the two systems may result in noncon-
1.3 Thistestmethodissuitableforthedeterminationofcore
formance with this standard.
loss, rms volt-amperes, rms exciting current, reactive volt-
1.9 This standard does not purport to address all of the
amperes, and related properties of flat-rolled magnetic materi-
safety concerns, if any, associated with its use. It is the
als under ac magnetization.
responsibility of the user of this standard to establish appro-
1.4 The frequency range of this test method is normally that
priate safety and health practices and determine the applica-
of the commercial power frequencies 50 to 60 Hz. It is also
bility of regulatory limitations prior to its use.
acceptableformeasurementsatfrequenciesfrom25to400Hz.
This test method is customarily used on nonoriented electrical
2. Referenced Documents
steels at inductions up to 10 kG [1.0 T] and for grain-oriented
2
2.1 ASTM Standards:
electrical steels at inductions up to 15 kG [1.5 T].
A 34/A 34M Practice for Sampling and Procurement Test-
1.5 Forreactiveproperties,bothfluxandcurrentwaveforms
ing of Magnetic Materials
introduce limitations. Over its range of useful inductions, the
A 340 Terminology of Symbols and Definitions Relating to
varmeter is valid for the measurement of reactive volt-amperes
Magnetic Testing
(vars) and inductance permeability. For the measurement of
A 343 Test Method forAlternating-Current Magnetic Prop-
these properties, it is suggested that test inductions be limited
erties of Materials at Power Frequencies UsingWattmeter-
to values sufficiently low that the measured values of vars do
Ammeter-Voltmeter Method and 25-cm Epstein Test
not differ by more than 15 % (Note 1) from those calculated
Frame
from the measured values of exciting volt-amperes and core
loss.
3. Significance and Use
NOTE 1—This limitation is placed on this test method in consideration
3.1 This test method may be used to determine the specific
of the nonlinear nature of the magnetic circuit, which leads to a difference
core loss, specific reactive power, specific exciting power,
between vars based on fundamental frequency components of voltage and
inductance permeability, and impedance permeability of flat-
current and current after harmonic rejection and vars computed from rms
rolled magnetic materials over a wide range of inductions and
current, voltage, and watt values when one or more of these quantities are
at frequencies up to 400 Hz for symmetrically magnetized test
nonsinusoidal.
samples.
1
This test method is under the jurisdiction of ASTM Committee A06 on
2
MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Methods. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Oct. 1, 2003. Published November 2003. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1988. Last previous edition approved in 1998 as A 889 – 93 (1998). the ASTM website.
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