Simulation impact method: it is the best test method to test the characteristics of soft magnetic dc at present. It is essentially a computer simulation method of artificial
impact method. This method was developed by the Chinese academy of metrology and loudi institute of electronics in 1990. Products include:
MATS-2000 magnetic material measuring device (discontinued), NIM-2000D magnetic material measuring device (metrology institute) and TYU-2000D soft magnetic direct current
automatic measuring instrument (tianyu electronics). This method avoids the cross - interference of the circuit to the measurement circuit and effectively inhibits the integration
The drift of the zero point also has the function of scanning.
2. Measurement method of ac characteristics of soft magnetic materials
Methods for measuring ac hysteresis loop include oscilloscope method, ferromagnetic instrument method, sampling method, transient waveform storage method and computer-controlled ac
magnetization characteristic test method. At present, the main methods of measuring ac hysteresis loop in China are: oscilloscope method and computer-controlled ac magnetization
characteristic testMethods. The main enterprises adopting wave device method are: big jeddah, yan qin nanometer and zhuhai grun, etc. Computer controlled ac magnetization testing
methods are mainly used by the Chinese academy of metrology and tianyu electronics.
1. Oscilloscope method: the test frequency is 20hz-1mhz, the working frequency is wide, the equipment is simple and the operation is convenient. But the test accuracy is low. The
test method is to use non-inductive resistance to sample the primary current and connect it to the X channel of the oscilloscope
Signal, the BH curve can be observed directly from the oscilloscope. This method is suitable for comparing and measuring the same kind of materials, and the test speed is fast,
but the magnetic characteristic parameters of materials cannot be accurately measured. In addition, due to the fact that there is no closed loop control between the integration
constant and the saturation magnetic sense, the correspondence of BH curve is also shown
The parameters can not represent the real data of the material and can be used in comparison.
2. Ferromagnetic instrument method: ferromagnetic instrument method is also called vector meter method, such as domestic CL2 type measuring instrument. The measuring frequency
is 45hz-1000hz. The device is simple in structure and easy to operate, but can only record the normal test curve. The design principle USES phase-sensitive rectifier to measure
the instantaneous value of voltage or current.And the phase of both, using the recorder to describe the BH curve of the material. Bt=U2au/4f*N2*S, Ht=Umax/l*f*M, where M is
the mutual inductance.
3. Sampling method: the sampling method is to use the sampling transformation circuit to convert the high-speed voltage signal into the voltage signal with the same waveform but
slow change speed, and use the low speed AD for sampling. The test data is accurate, but the test frequency reaches up to 20kHz, and it is difficult to adapt to magnetism
Requirements for high frequency measurement of materials.
4, using computer control ac magnetization characteristic test method: this method is to make full use of the computer control and software processing capacity design of measuring
is also a living after product development direction. The design adopts computer and sampling circuit for closed-loop control.
So that the whole measurement can be arbitrary. Once the measurement conditions are input, the measurement process is automatically completed and the control can be automated. The
function of measurement is also very powerful, and almost all parameters of soft magnetic materials can be accurately measured.