10 replies to this topic

[KBMB]

Hello all,

 

Can anyone offer their insight on whether or not it is necessary to use a SEALED product containing the metal detector test strips to test the metal detector?

Is it recommended that the product is sealed.

 

Any and all advise would be greatly appreciated.

 

Thank you.

 

KBMB

[Scampi]

In a perfect world you would open a package, embed the test bars into your product and then pass it through.

 

However, that would require the bars to be sterilized prior to use etc etc etc

 

You do NEED to include the packaging itself as metal parts are used the in manufacture of well, everything. So if you do not include the packaging, you may miss metal contamination

[MsMars]

You just need to replicate the position in the product that would be "worst case scenario" or hardest for your detector to find, which is usually as close to the middle of the product as possible. In a perfect world you should also attempt to replicate your actual product condition as closely possible.  However if you are doing hourly checks and it's time consuming or costly to do this (since you're contaminating product), I'd recommend at least doing a daily or weekly check in a sealed package to validate that the check is just as effective in a sealed package than in an unsealed package.

[012117]

Hi, KBMB.

 

In terms of principle of MD, MsMars is correct, that you should always target that your test piece must be as much as possible be situated in the center of aperture of metal detector (which is the middle). In terms of where to place, here is what I recommend:

 

Validate the MD setting using the worst case scenario. Meaning which of your product specification which you may think will affect your detection (Product effect,e.g. which has the most moisture content, which ingredient may be "conductive", packaging etc) and false rejection.

 

Once your settings is established, passed the product with test piece in the aperture (estimate) and over the product (should you have smaller product that the middle of aperture this is much easier), make tests that is statistically sound for you to compare data.

 

If there is no significant difference between the signal of different test piece location, document it and in your hourly monitoring, you can have the confidence that the performance is the same even if you place it in the middle of middle detector.

 

If there is significance difference (meaning the test piece in the middle have very small difference between the product without contaminant), I would suggest you monitor always inside (as there is significant product effect).

[Charles.C]

Hello all,

 

Can anyone offer their insight on whether or not it is necessary to use a SEALED product containing the metal detector test strips to test the metal detector?

Is it recommended that the product is sealed.

 

Any and all advise would be greatly appreciated.

 

Thank you.

 

KBMB

 

One alternative is to simulate the product environment  by embedding the test piece within something like latex. Needs to be validated of course.

[MsMars]

One alternative is to simulate the product environment  by embedding the test piece within something like latex. Needs to be validated of course.

 

With the abundance of latex allergies, I wouldn't recommend that particular material.  Something similar and food-safe, though. 

[Charles.C]

With the abundance of latex allergies, I wouldn't recommend that particular material.  Something similar and food-safe, though. 

 

Hi Ms Mars,

 

Indeed, it's a question of availability.

 

We (hopefully conservatively) used slabs in sealed boxes.

 

I was interested to note that FSMA apparently somewhat "avoided" the foodsafe(human-safe?) issue of latex gloves. Globally still in common use afaik.

 

https://www.foodqual...oves-food-safe/

[MsMars]

Hi Ms Mars,

 

Indeed, it's a question of availability.

 

We (hopefully conservatively) used slabs in sealed boxes.

 

I was interested to note that FSMA apparently somewhat "avoided" the foodsafe(human-safe?) issue of latex gloves. Globally still in common use afaik.

 

https://www.foodqual...oves-food-safe/

 

It is interesting that the issue has been avoided by regulatory bodies, and I applaud both the medical and the food industry for taking it upon themselves to nearly eliminate latex, although may be more driven by risk to employees as much as consumers.  I myself developed a latex allergy while working in a laboratory and using latex gloves daily, and after some research it seems that it is a common phenomenon.   

[Gerard H.]

Dear KBMB,

 

In the link below, you will find an article about the place of the test pieces. I hope, that it can help you further to develop your metal prevention program.

 

https://qualitic4u.c...ction/#more-769

 

Kind regards,

 

Gerard Heerkens

[Charles.C]

Dear KBMB,

 

In the link below, you will find an article about the place of the test pieces. I hope, that it can help you further to develop your metal prevention program.

 

https://qualitic4u.c...ction/#more-769

 

Kind regards,

 

Gerard Heerkens

 

Hi Gerald,

 

Thks for above. Usefully succinct.

 

The English is a little strange. Cadence is usually a musical term. Probably meant sequence.

 

As implied in article, the sensitivity is evaluated in 2 respects - specific location in product unit and in respect to the overall product flow on conveyor.

 

I speculated a few possible additions, eg - (a) how many repeat runs to make, (b) procedure  if top of product is below MD axial centre-line, © a caveat regarding non-spherical contaminants, eg needles.

 

JFI I think the usual text book statement as to line of minimum sensitivity assumes a symmetrical array.

[Gerard H.]

Dear Charles,

 

Many thanks for your feedback.

 

The pace of the line was meant with the term "cadence"... Here in the French industry everyone speaks about "line cadence" (=la cadence de la ligne). There it came from (and yes, I love to play piano). It will be modified and I will see whether I can integrate your other remarks in the article. 

 

I wish you a nice day!

 

Kind regards,

 

Gerard

Edited by Gerard H., 30 October 2018 - 02:42 PM.