This standard uses the volt-ampere method to measure the amplitude permeability μa of annular specimens made of soft magnetic alloy (iron-nickel) strip at room temperature (10-35°C). The measurement frequency is 60Hz to 10kHz. Other measurement methods are allowed under the premise of ensuring the measurement error. GB/T 5026-1985 Measurement method of amplitude permeability of soft magnetic alloys GB/T5026-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
The measurement method of amplitudepermeability of soft magnetic alloysUDC 621. 318. 13
：669.1524
: 621. 317.41
GB5026-85
This standard uses the volt-ampere method to measure the amplitude permeability a of annular specimens prepared from soft magnetic alloy (iron-nickel) strips at room temperature (10-35C). The measurement frequency is 60Hz to 10kHz. Other measurement methods are allowed under the premise of ensuring the measurement error. 1 Specimen
The specimen shall comply with the provisions of GB3658--83 "Measurement Method of AC Magnetic Properties of Soft Magnetic Alloys". 2 Measurement principle, circuit and instruments used
2.1 The volt-ampere method is used to measure the amplitude permeability a of the soft magnetic alloy. There are two methods for measuring the peak value of the magnetic field intensity: the bee value voltage drop method and the mutual inductance method. The peak voltage drop method uses a bee value voltmeter to measure the voltage peak value U across the series resistor R in the primary circuit, and calculates the peak value H of the magnetic field intensity; the mutual inductance method is to connect the primary coil of the AC mutual inductance coil in series in the primary circuit instead of the resistor R, and use an average value voltmeter to measure the average value of the secondary induced voltage of the AC mutual inductance coil to calculate the peak value H of the magnetic field intensity. The peak value of the magnetic induction intensity is measured by using an average value voltmeter to measure the average value U of the induced voltage across the secondary winding N of the sample, and calculate the peak value B of the magnetic induction intensity of the sample under the magnetic field. The ratio of B to H is the amplitude permeability a of the sample under the magnetic field. The principle circuit of the volt-ampere method is shown in the figure below 2.2
（）Peak voltage drop method
In the figure: E
AC magnetizing power supply;
A frequency meter;
Peak voltage meter:
National Bureau of Standards 1985-03-28 Issued
Principle circuit of the volt-ampere method
）Mutual induction method
1986-01-01 Implementation
Average voltage meter;
AC mutual inductance coil;
Series resistance;
N, exciting winding;
N2-———secondary winding.
GB 5026—85
2.3 The technical indicators of the instruments and components used in this standard should meet the following requirements. 2.3.1 AC magnetizing power supply E~
Frequency range: 40Hz~10kHz;
Frequency stability: no more than ±0.1% in 20min: Output voltage stability: no more than ±0.1% per min; Output voltage: 0~50V (continuously adjustable in steps); Output power not less than 10W.
2.3.2 Peak voltage meter
Frequency range: 40Hz~100kHz;
Measurement range 1mV~10V;
Input impedance not less than 1MQ;
Accuracy not less than Class 1.0.
2.3.3 Average voltage meter
Frequency range: 40Hz~10kHz;
Measurement range: 1mV~~100V;
Input impedance not less than 1MQ;
Accuracy not less than Class 1.0.
2.3.4 Frequency meter (Hz
The accuracy of the frequency meter shall not be less than 0.1 level.
2.3.5 Series resistor R
The resistance range is 12 to 102 non-inductive resistor. Within the measurement frequency range, the accuracy shall not be less than 0.2 level. 2.3.6 AC mutual inductance coil M
A ring-shaped hollow AC mutual inductance coil is used, and the mutual inductance coefficient is 0.5mH to 1mH, and the accuracy is not less than 0.2 level. 2.3.7 The excitation winding NI and the secondary winding N2 are recommended to be 30 turns to 50 turns. Use yarn-covered wire or enameled wire with a diameter of about 0.3mm for winding. 3 Measurement steps
3.1 First, demagnetize the sample to be tested. The method shall be carried out in accordance with the requirements of 6.1 in GB3658--83. 3.2 When this standard is used to measure the amplitude magnetic permeability of the sample, the distortion of the magnetic induction waveform shall not exceed 10%. When using the mutual inductance method, the magnetizing current is required to change monotonically between the positive and negative peak values. 3.2.1 The peak voltage drop method is used to measure the peak value of the magnetic field intensity. The relationship between the voltage peak U across the series resistor R and the magnetic field intensity peak H is shown in formula (1): bzxZ.net
where: H
peak magnetic field intensity, A/m;
N.—· Number of turns of the excitation winding;
a—-average diameter of the sample, m;
resistance value, Q;
——peak voltage across the resistor R, V. GB 5026-85
3.2.2 The peak value of the magnetic field strength is measured by the mutual inductance method. The relationship between the average value U of the secondary induced voltage of the AC watt inductor and the peak value H of the magnetic field strength is shown in formula (2):
4 yuan fMa
Where: f—…-frequency, Hz;
M—-mutual inductance coefficient, H;
T—average value of the secondary induced voltage of the AC mutual inductance coil, V. (2)
3.3 When measuring at a certain frequency and a certain magnetic field, select the frequency of the magnetizing power supply at the specified value and adjust the output of the magnetizing power supply to a certain value. If the peak voltage drop method is used, the indication value of the peak voltage meter connected to the two ends of the series resistor R should be recorded, and the peak value H of the magnetic field strength should be calculated by formula (1). If the mutual inductance method is used, the average value of the voltage connected to the two ends of the secondary of the AC mutual inductance coil should be recorded. The indicated value of the voltmeter is obtained, and the peak value H of the magnetic field intensity is calculated by formula (2). At the same time, the indicated value of the average voltmeter at both ends of the secondary winding of the sample is recorded, and the peak value B of the magnetic induction intensity of the sample under the magnetic field is calculated by formula (5). Then the amplitude permeability of the sample under the magnetic field is calculated by formula (6). 3.4 The measurement steps under other magnetic fields are carried out according to 3.3. 3.5 When measuring at the same frequency and different magnetic fields, the measurement should be made from the low magnetic field to the high magnetic field. When measuring at different frequencies and different magnetic fields, demagnetization should be performed before each frequency change, and then the measurement should be made from the low magnetic field to the high magnetic field. 4 Calculation
4.1 The average diameter of the sample is calculated by formula (3): a
Where: a--average diameter of the sample, m;
d--inner diameter of the sample, m;
D--outer diameter of the sample, m.
4.2 The cross-sectional area of ​​the sample is calculated by formula (4): d+D
Wherein: S---the cross-sectional area of ​​the sample, m\; m
-the mass of the sample, kg;
the density of the sample, kg/m2.
4.3 The peak value of the magnetic induction intensity of the sample is calculated by formula (5): B
Wherein: B
-the peak value of the magnetic induction intensity, T;
U,——the average value of the secondary induced voltage, V; N.——the number of turns of the secondary winding.
4.4 The amplitude permeability of the sample is calculated using formula (6): 118
(3)
(5)
Where: a-
Amplitude permeability, H/m
GB 5026-85
4.5 The relative amplitude permeability of the sample is calculated using formula 7): Par
Where: r—
Relative amplitude permeability;
Magnetic constant, 4 yuan×10-7H/m.
To meet the requirements of this standard, the error of measuring amplitude permeability shall not exceed ±4%. 6 Calibration
The instruments used in this standard shall be calibrated regularly by the metrology department. (6)
(7)
GB5026-85
Appendix A
(reference)
The formulas used in this standard are all in the international system of units. If the Gaussian system of units is used, the corresponding formula is: A-0.4Ni
Where: H-peak value of magnetic field intensity, Oe;
N,——number of turns of exciting winding;
a.—average diameter of the sample, cm;
R-—resistance value, 2;
U——peak voltage, V;
Where: f-—frequency, Hz;
M-mutual inductance, H;
—average voltage, V.
Where: d----inner diameter of the sample, cm;
U——outer diameter of the sample, cm.
--Cross-sectional area of ​​a sample, cm\;
Where: S
m\--mass of the sample, g;
p---density of the sample, g/cm.
Where: B--peak value of magnetic induction intensity,Gs; U2—average value of secondary induced voltage, V;
Nz—number of turns of secondary winding.
Where: ua——amplitude permeability, Gs/Oe. Additional remarks:
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Dalian Steel Plant.
The main drafters of this standard are Dong Anzhi, Wu Longpeng and Chen Mengguang. 120
（3）
（5）
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