Permanent Magnet Magnetic Field Strength
For magnet users, how to confirm the grade and magnetic properties are still a long standing issue. Most of users can’t get the value of main magnetic parameters by themselves. In this case, the relative measurement of magnetic properties is the best solution. The relative measurement of magnetic properties includes magnetic field strength, magnetic flux and magnetic moment. For magnetic flux and magnetic moment testing, different specification need different testing coil, and this is the reason why the magnetic field strength is the most popular testing method among the relative measurement.
How to get the magnetic field strength of magnet?
The magnetic field strength of magnet can be measured by Gauss Meter, or Tesla Meter. Now, many magnet users have their own Gauss Meter, and also establish the acceptance criteria of magnetic field strength. For multi-polar magnet, the magnetic field strength will be measured by Magnet Analyzer.
According to above equation, the value of magnetic field strength is affected by magnet’s grade, dimension and testing position. It should be noted that the measured value of Nickel-coated magnet’s magnetic field strength will lower than Biot-Savart simulation value due to shielding effect from ferromagnetism Nickel coating.
For multi-pole magnetization and complex conditions, the designer will learn its strength and distribution of magnetic field by finite element analysis software (FEA or FEM), then accurately estimate the magnetization state and flux distribution of whole magnetic circuit system. The finite element analysis is a powerful tool in development stage of magnet product.
The finite element analysis technology is widely used in the design of sensor magnet, magnet assembly, and complex magnet system. MPCO have plenty of experience in finite element analysis of magnet application. MPCO eager to provide technical solution to customer in the development and cost reducing stage.
The calculated values and simulation results are for reference only, and the deviation between measured value and calculated value from various reasons. The operator need to avoid the deviation from instrument and operation process.
In order to ensure the hall element free of crack, the instrument manufacturer usually make an epoxy resin coating upon the hall element. This coating also produce an air gap, and this air gap is often overlooked during calculation and simulation. traditional ferrite education magnet