Rare Earth Magnet Tolerances

Hello,

My food facility was recently audited and a comment we got was that we have to define what our out of tolerances for our Rare Earth Magnet is via documentation so what would out of tolerance for a Rare Earth Magnet be?

Also, how do you determine the tolerance of Rare Earth Magnets? Is it facility or manufacturer based? Currently, we perform a pull test on the magnet based on tolerances that I have no idea how were established. 

Hi oahr1996,

:welcome:

Welcome to the IFSQN forums.

This is something that should have been defined when the plant was commissioned/the magnet installed.

From BRCGS:

The magnet’s strength should be designed to ensure that it is sufficient to capture metal foreign bodies. A number of factors should be considered when determining the correct strength; for example, the type of product (e.g. the size of the food particles), the width of the conveyor belt, chute or other equipment in which the magnets are located, and the flow rate of the food or raw material.

If you don’t have tolerances then I would contact the magnet manufacturer and discuss. It might be a case of validating that the magnet is effective in your application again and establishing acceptable tolerances.

Also note that BRCGS Guidance offer this:

Good practice for monitoring a magnet’s performance includes locating a second ‘policing’ magnet as close to the first as possible. Any metal found on this second magnet indicates that the ‘process’ magnet is not performing satisfactorily and is failing to remove all metal particles.

Kind regards,

Tony

Thank you so much, Tony!