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Space environment test methods for satellite components - Magnetic test
1 Scope
1.1 Subject content
This standard specifies the test purpose, technical requirements, test procedures and data processing methods for magnetic test of satellite components.
1.2 Application scope
This standard is applicable to the magnetic test of satellite components (hereinafter referred to as test pieces), and may be referred to by other spacecraft components.
1.3 Classification
The test methods in this standard are classified as follows:
a. magnetic moment measurement;
b. magnetic field measurement;
c. demagnetizing test.
2 Normative references
GJB 1027 Environmental test requirements for satellites
QJ 1169 Rules for drafting research and development documents
3 Definitions
3.1 remanent magnetic moment
magnetic moment existing when the test piece is not working
3.2 working magnetic moment
magnetic moment existing when the test piece is working
3.3 main coil
device that can offset the geomagnetic field in the center of the coil by adjusting the current to present a zero magnetic field or a stationary magnetic field
3.4 magnetic field inhomogeneity
absolute value of the difference between the maximum or minimum magnetic field intensity and the central magnetic field intensity in a specified space, whichever is greater
3.5 homogeneous space
space where the magnetic field inhomogeneity is less than the required value in the center of main coil
3.6 magnetic field instability
change value of the magnetic field within the specified time
3.7 magnetizing and demagnetizing coils
device that can generate the required magnetizing field or demagnetizing field by adjusting the current in the coil
4 General requirements
4.1 Test environmental conditions
4.1.1 Laboratory environmental conditions
Unless otherwise specified, the laboratory environmental conditions are generally as follows:
a. meeting the requirements of GJB 1027, 4.1;
b. cleanliness: Class 100,000.
4.1.2 Environmental magnetic field conditions
a. there is no magnetic storm or strong industrial magnetic field interference, and the influence of external magnetic field interference on the magnetic induction intensity in the center of the main coil is less than 2nT;
b. there shall be no magnetic substance with magnetic induction intensity above 2nT in the center of the main coil near the test site.
4.2 Test sequence
The magnetic test is generally carried out in the following sequence:
a. initial magnetic moment (or magnetic field) measurement;
b. magnetizing test;
c. magnetic moment (or magnetic field) measurement after magnetizing;
d. demagnetizing test;
e. magnetic moment (or magnetic field) measurement after demagnetizing.
4.3 Test piece and its installation requirements
4.3.1 The overall size of the test piece shall not exceed the homogeneous space of the main coil, and the maximum allowable size shall be 0.5m×0.5m×0.5m.
4.3.2 The mass of the test piece shall not exceed the bearing capacity of the turntable, generally not more than 50kg.
4.3.3 The surface of the test piece shall be clean and be free from ferromagnetic substances adhering to it.
4.3.4 When the test piece is installed, its geometric center shall coincide with the intersection of the two rotation axes of the turntable.
4.3.5 The control and test equipment for test piece shall be more than 10m away from the center of the main coil. The length of power supply cable and measuring cable shall meet the measurement requirements.
4.4 Requirements for test equipment
The test equipment generally include main coil, demagnetizing coil, turntable, etc.
4.4.1 Main coil
a. Zero magnetic field: the magnetic induction intensity is less than ±10nT, the size of homogeneous space is generally not less than 0.5m×0.5m×0.5m, the inhomogeneity is better than ±10nT, and the instability is better than ±1.5nT/h;
b. Stationary magnetic field: the magnetic induction intensity is within 0~60,000nT, and its size of homogeneous space, inhomogeneity and instability are the same as those of zero magnetic field;
c. Size of access channel is generally not less than 0.5m×0.5m;
d. The magnetic field in the center of the main coil is generally tracked and compensated by the compensation system for the interference of the external magnetic field.
4.4.2 Turntable
a. The turntable shall be able to rotate 0°~360° around the vertical axis and 0°~±180° around the horizontal direction continuously, with angle indication;
b. The intersection of the two axes of the turntable shall coincide with the center of the main coil;
c. The size and bearing capacity of the turntable shall meet the test piece requirements.
4.4.3 Magnetizing and demagnetizing coils
a. They can generate 5mT magnetizing/demagnetizing fields;
b. The demagnetizing frequency is generally less than 3Hz;
c. The magnetizing and demagnetizing coils are generally placed in the center of the main coil, and their centers shall coincide with the center of the main coil.
4.4.4 Measuring bracket
The measuring bracket is used to install magnetometer probes (probes for short). Generally, it shall be able to install more than three probes, and it has a height-adjustable guide rail for adjusting the position of the probe.
4.4.5 Equipment structure materials
The structures of main coil, magnetizing and demagnetizing coils, turntable and measuring bracket are made of materials with magnetic susceptibility less than 5×10-6.
