Calibration of metal detectors

Hello All,

My company is doing major reconstruction moving lines from an old to new upgraded areas.

On all processing lines metal detectors are CCP’s. Metal detectors are calibrated on an annual basis.  Now, when we decommission a line in one area and move a line in new area. Do we have to calibrate metal detectors before line start to run again?  We still have 6 months until regular calibration date.

Thank you in advance.

SuperP

I would consult with your MD manufacturer's equipment specs.  The first check is in ensuring that the new setup has an acceptable "metal free zone".  It may or may not need a calibration, but drastic changes to environment such as temperature, ambient noise, vibrations, conveyor speed changes, reject mechanism input (proper timing/pressure air flow, new reject bin testing), etc, might require a major risk analysis and systematic prove-up to the process change.  If you can not emulate the same reject thresholds for the same product from one area to the next, it's time to call in the experts.

 

I would.  It is a new environment and recertifying is essential to validating the equipment. 

Hello All,

 

My company is doing major reconstruction moving lines from an old to new upgraded areas.

On all processing lines metal detectors are CCP’s. Metal detectors are calibrated on an annual basis.  Now, when we decommission a line in one area and move a line in new area. Do we have to calibrate metal detectors before line start to run again?  We still have 6 months until regular calibration date.

 

Thank you in advance.

 

SuperP

Dear SuperP,

So what do you actually mean by "calibration" ?

Rgds / Charles.C

Hello All,
 
My company is doing major reconstruction moving lines from an old to new upgraded areas.
On all processing lines metal detectors are CCP’s. Metal detectors are calibrated on an annual basis.  Now, when we decommission a line in one area and move a line in new area. Do we have to calibrate metal detectors before line start to run again?  We still have 6 months until regular calibration date.
 
Thank you in advance.
 
 

Dear SuperP,
 
So what do you actually mean by "calibration" ?
 
Rgds / Charles.C

I would consult with your MD manufacturer's equipment specs.  The first check is in ensuring that the new setup has an acceptable "metal free zone".  It may or may not need a calibration, but drastic changes to environment such as temperature, ambient noise, vibrations, conveyor speed changes, reject mechanism input (proper timing/pressure air flow, new reject bin testing), etc, might require a major risk analysis and systematic prove-up to the process change.  If you can not emulate the same reject thresholds for the same product from one area to the next, it's time to call in the experts.

 

Thank you for your a very good comment. I will review those steps with Food Safety team.

Regards,

SuperP

Dear SuperP,

Calibration or recertification of metal detectors completed by supplier once a year.

Sorry to have to repeat myself but what (in yr case) does this mean ??

The point is that for many (most?) applications the primary calibration test is simply  whether the unit  maintains its sensitivity, ie rejects/kicks out the standard test piece which defines correct machine performance under the appropriate operating matrix/sample presentation conditions. I would expect the MD user to "continuously" validate this in routine usage.

The rest is frequently a "tune-up" bonus for the supplier / experts, particularly as many users are anyway unlikely to understand the technical details generated. It's a bit like the last page of yr HDTV operating manual. :smile:

Nonetheless, if it is found convenient  to accumulate annual COCs for audit purposes, I suppose this may also be a  secondary  justification for the expenditure. :smile:

Rgds / Charles.C

Dear SuperP,

 

 

Sorry to have to repeat myself but what (in yr case) does this mean ??

 

The point is that for many (most?) applications the primary calibration test is simply  whether the unit  maintains its sensitivity, ie rejects/kicks out the standard test piece which defines correct machine performance under the appropriate operating matrix/sample presentation conditions. I would expect the MD user to "continuously" validate this in routine usage.

 

The rest is frequently a "tune-up" bonus for the supplier / experts, particularly as many users are anyway unlikely to understand the technical details generated. It's a bit like the last page of yr HDTV operating manual. :smile:

 

Nonetheless, if it is found convenient  to accumulate annual COCs for audit purposes, I suppose this may also be a  secondary  justification for the expenditure. :smile:

 

Rgds / Charles.C

Thank you Charles,

I just want to be ready and not surprised after the fact.

Honestly, I prefer to complete risk assessment and it will be also accepted by auditors.  

Regards,

SuperP

I have to agree with Charles.  Don't you test the verification of the calibration regulalrly with Ferrous, non-ferrous and stainless steel test pieces... We have to regularly move metal detectors when we change the line set-up. we verify the calibration before each product but only have them "calibrated" once a year by an outside company.  What they do is more fine-tuneing than claibrating.  I agree however though, that if they are going to be moved and bumped around a lot, suffer temper ature changes etc.. than maybe a third party calibration is a good idea but you could always check that they adequately reject the test pieces before -hand.  Your best answer would be from the metal detector manufacturer however.

I would advise purchasing another set of calibrated test sticks (shouldn't cost too much) and running them through the metal detector before and after moving the machine and comparing results. This will give you some idea of fluctuations in sensitivity between areas. There will still be variances due to humidity and temperature, whilst showing up any vibration issues from constant movement. Give it a tolerance of 500 or so. It will show any auditor that you have considered this risk, invested resources and set a corrective action plan in place. Chances are there will not be any issues - metal detectors are fairly tough pieces of kit in my experience. I'm not sure what your manufacturer would be able to tell you, they will most likely say they have not trialed their piece of equipment to such exact changes and will most likely not recommend movement. Hell, they'll most likely say buy another one! 

Dear shea quay,

I deduce that yr MD actually has a meter.

So lucky ! :biggrin:

Rgds / Charles.C