Metal Detection Limits

We manufacture theroformed trays for the food industry, due to pressures of of customers demanding we metal detect all produt, we purchased two metal detectors (the person who origianaly purchased these is no longer with the company).


I have been having discusions with senior managment about the test pieces for testing for Ferrous.nonferrous & stainless steel.
When we orrigially purchased our metal detector we Ferrous & non ferrous @2.5 & stainless steel @3
Some time over the years someone has purchased Ferrous 3.00, non ferrous @ 2.5 & stainless steel @3.00.
I have the manufactures guidlines for the machines we use.
Can any one tell me if there is a set standard we should be following

Dear kaz,

IMEX, customer's expectations vary. However I wud hv guessed you will satisfy most people with the most demanding of the options you hv mentioned, assuming they don't give false negatives.

Rgds / Charles.C

One of the BRC Guidelines is on the subject of metal detection so you may find this useful. We typically refer to this document for the justification of critical limits etc...
You can see details at:
http://www.tsoshop.c...d=9780117035737
Costs about £10.
Regards,
Russell

Hi Kaz,

Try the Tesco Metal Detector Guide Doc it is very good!COP_for_Metal_Detection___X_ray_Systems__375_.doc   2.37MB   241 downloads

Dear caddyshack,

Thks for the document (is it already included in the Caz compilation ? was too lazy to check ).

I agree it's a nice piece of work (I do love the Tesco term "aspiration").

One minor nitpicking -

The test pieces must be passed through the detector in the centre of the aperture because this is the least sensitive part. This could be in the centre of the pack, on top or underneath. If the test piece is not in the centre of the pack then it must be attached to the product.

What do you do if the product top surface is below the aperture centre ? Put a book under it ?

The tesco required sensitivities look similar to the ones in the Loma document posted earlier -

some_met.det.guideline_sensitivities.png   6.99KB   101 downloads

Sadly, kaz's standard pieces may be inadequate for tesco unless using very high / wet products etc. Or maybe this is not the whole story, IMEX it is very easy to get false positives for various products when looking for the top end sensitivities.

Rgds / Charles.C

PS @allsafe, thks for yr link, perhaps IFSQN members shud get a discount
(any chance you cud post the "conclusion"?)

We use the FDA guidance as validation for our critical limits.

http://www.fda.gov/I...l/ucm074554.htm

Personally I don't see anything wrong with your limits. For me the Stainless Steel one is the critical one as that's probably what most of your kit is made out of.

Just remember to get all of your equipment serviced with these test pieces if you intend to stick with them, alternatively buy some more from ICteststick if the 2.5mm would still work and remove the 3.0mm Ferrous - they're only £6 each.