Rather than start a new thread with the same name, I'm trying to hop onto this one to get an answer:
We have a liquid trap magnet (not a CCP) in a chocolate line. We check it once a day, but have never validated it. I believe it's placement is more for equipment preservation than for food safety (placed after a pump and before a tempering unit). Because we also have in-line filters (which will trap more than metal) both upstream (before the pump) and downstream (after the tempering unit) of this magnet, we have rarely (if ever?) had a finding so I haven't spent too much time thinking about it.
I'm trying to figure out how small a piece of metal the magnet can trap. I don't have the vaguest idea how to translate a pull reading (gauss) to an actual piece of metal in a liquid chocolate stream. I have two related questions:
1. How do I figure out how small a piece my magnet can trap in a running situation (validation)? To do a dry test doesn't strike me as valid.
2. How do I check that regularly to make sure it's working ((verification)? -- My guess is this can be determined with a pull strength test once I have a baseline.
Looking forward to your comments!