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What is Demagnetization?

PPS pull testing

What is Demagnetization?

The strength of a magnet, usually measured in gauss or pull strength, is one factor that determines the effectiveness of a magnetic separator. In the food industry, equipment is exposed to a variety of different temperatures, environments, products, and other circumstances that can affect the magnet’s strength.


High-quality permanent magnetic separators can retain adequate strength & effectiveness for many years, however, low-quality cheap systems can lose their strength rapidly – despite being 10,000 gauss or higher upon supply!


Loss of magnetic strength is referred to as ‘demagnetization’.


Some of the most common influences of demagnetization include:
• temperature (heating past the Curie point)
• oxygen absorption
• resonant vibration
• thermal shock

  • electrical arcing (welding around magnets)
    • rough handling (such as dropping or banging)


Once a rare earth magnet’s strength is lost, it is lost forever – you cannot ‘recharge’ these magnets strength as you can a battery.  This is why it is important to regularly test your magnetic separators strength and take note of any loss of strength over time to determine if the magnet needs replacing.


Visit our MAGNATTACK magnetic separator product pages to learn more about our magnetic separator solutions and how the product design can help avoid some of the above common influencers or demagnetization.



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