65 replies to this topic

[mawulidogbo]

It depends on the height of the metal detector. The middle of the middle is the most insensitive part of the metal detector. I am sure if the test stick is placed on top then its close to that site.

 

Bw, Mawuli

[Charles.C]

It depends on the height of the metal detector. The middle of the middle is the most insensitive part of the metal detector. I am sure if the test stick is placed on top then its close to that site.

 

Bw, Mawuli

 

^^^^(red) - Interesting Location !

[Tony-C]

^^^^(red) - Interesting Location !

 

Also known as the centre!

[Scampi]

Middle of the middle makes perfect sense

 

AKA the geometric mean of the item in question

[AJL]

Hi, we put the test Pieces on top of the product, and we were asked if we had made a validation vs them being lower in the product.
It isn't reasonable to insert the test Pieces in the product, as it is a Frozen product and they would become soiled and potentially lost.
How can I satisfy the auditor? It needs to be a very basic explanation for me and practical 🙈

[Tony-C]

Hi, we put the test Pieces on top of the product, and we were asked if we had made a validation vs them being lower in the product.
It isn't reasonable to insert the test Pieces in the product, as it is a Frozen product and they would become soiled and potentially lost.
How can I satisfy the auditor? It needs to be a very basic explanation for me and practical 🙈

 

Hi AnnMou,

I would be doing annual validation with test pieces on top and inside the product to prove that both are effective. Then with test piece on top for routine daily checks.

Kind regards,

Tony

[AJL]

Thank you! How many times do you think I should pass the product through for it to be a decent validation?

Or how many times should I repeat?

Thanks!!

[Charles.C]

Thank you! How many times do you think I should pass the product through for it to be a decent validation?

Or how many times should I repeat?

Thanks!!

Hi AJL,

 

Strictly yr current procedure may not be accurate unless top is fortuitously on the axial line of MD, otherwise result is potentially optimistic.

 

As to number of runs for validation, opinions vary + it may depend on yr results (repeats can be +/-). The Literature has examples up to 30 runs but 3-5 seems a little more respectable. Some specific SOPs exist on this Forum since this also sort of relates to choice of CL.

Some people do insert metal samples in products before freezing. Another (auditorially acceptable IMEX) solution to yr query is using a dummy packing box filled with self-setting foam and metal samples appropriately positioned inside. It's easier to directly respond if you also make frozen IQF products + you can then  "calibrate" the dummy box also.

Another common audit expectation is front and back where the height could also be varied albeit not inside the product.

[GMO]

Thank you! How many times do you think I should pass the product through for it to be a decent validation?

Or how many times should I repeat?

Thanks!!

 

I'd ask your supplier or service contract owner to validate it for you.  

[GMO]

Hi, we put the test Pieces on top of the product, and we were asked if we had made a validation vs them being lower in the product.
It isn't reasonable to insert the test Pieces in the product, as it is a Frozen product and they would become soiled and potentially lost.
How can I satisfy the auditor? It needs to be a very basic explanation for me and practical

 

The simple answer is... it depends.  If the top of the product is the closest point to the centre of the aperture, there are decent references you can use to say that's sensible positioning.  If it's not, as I said above, get your supplier or service contractor to validate it.  You may want to produce test packs where you actually drill into what would be the closest to the centre and compare outputs for example as part of that validation, not as a routine test, but they should be able to advise.

Edited by GMO, 09 March 2022 - 04:23 PM.

[825tzy09]

Hi, Cakeman.

 

None of the options is the best answer as the best location is where the test piece is located relevant to the center of aperture of the MD. While product effect is highly considered in MD, the effect can still be experienced be it above or inside product pouch. The effectivity can still be monitored/verified if test piece is placed at the center aperture.

 

Having said, you may also want to consider what is the best orientation to check your product.

[DSTechnicalManager]

Hello,

 

I think this information should have been given to you by the company who calibrated and validated your metal detector.

[NicholasWynne]

What is the general consensus on the placing of test pieces when checking a metal detector

 

This heavily relies on the product being tested, and the metal detector being used.

 

The goal should be to have the test piece in the centre of the aperture (weakest detection point). Depending on product dimensions, this could be on top or inside.

 

However, if detection due to product density is in question, additional testing can take place inside the product, regardless of the position in relation to the aperture. (this would be additional, not instead of the center)

 

Talking to your manufacturer and referring to your specific standard is always the best way to get tailored information.

[RobiWanKenobi]

Good morning everyone,

I must assume, I am quite new to MD. I got used to X-Ray, but then got a new job with other method of foreignBody-Detection. For now I understand, that the weakest Point if this Detectors is in the middle of the apperture, because it is most far away from the coil. But how do I regard the product in this?

We are handling IQF Fish fillets of smaller fishes (not like salmon or tuna, more like mackerel or herring) in bags and cardboard-boxes.

To me the product influences the sensitivity through minerals, water and whatsoever. But when the wand is placed on top of the product, there is no influence on the magnetic field, because no product between coil and wand. Or am I thinking wrong?

For now we are trying to place the wands inside a bag of lose fillets, no exact positioning possible. Testing would be much easier and much closer to the apertures center when the wand can be fixed on top of the bag or box and led through the MD. Is the product still influencing the Detection this way?

Also Manufacturer says Center of Coil, but first I want to make sure before touching 15yr old SOP of this companies CCP.

 

Thank you very much.

[SHQuality]

The product can mask the presence of metal in certain metal detectors. You should always put the test piece INSIDE the product for the most accurate reading.

[Madam A. D-tor]

The product can mask the presence of metal in certain metal detectors. You should always put the test piece INSIDE the product for the most accurate reading.

When the product and the testpiece are going through the metal detector at the same time, the effect of the product will be taken in consideration.

 

The hardest place to detect is the geometric centre of the metal detector. The test piece should be in the geometric centre when passed through the detector toegether with the product pack. Ideally the size of the packs and the size of the metal detector are such that the top of the pac is under or on the geometric center. You want to prevent that product that might be contaminated are on the hardest place to detect. Therefore in such cases the test pieces is the best placed on top of the pack in the center of the metal detector.