Metal Detector Frequency and Verification

Hi all,

New to metal detectors as I came for the beverage industry.

I am just after some thoughts.

Currently our checks on the metal detector are every 4 hours and i feel that is a very long time. Can i ask, what time frames others have.

Is it just a matter of how much product you need to hold and rework if there is a fail?? or is there a direct method that will tell you the required frequency. They appear to have no justification as to why it is every 4 hours.

Lastly, we have it calibrated annually and as mentioned above checked every 4 hours by the operators. should there be another internal verification/validation between calibration periods or whats the recommended practice?

Cheers,

Rob

It depends on what type of food safety standard you follow.

We are BRC Food and do at least 4 checks during an 8 hour shift. One at the start, two during and one at the end of each shift.

Also if there's some type of change in production (either packaging or raw material).

I guess it's the minimum, both in terms of BRC standard regulation and time to do it. I mean, the staff do have other things to do as well  :shades:

We do an annual calibration and this seems to be sufficient.

Talk to your equipment provider and discuss if it's neccessary to increase calibration.

Hi all,

 

New to metal detectors as I came for the beverage industry.

 

I am just after some thoughts.

 

Currently our checks on the metal detector are every 4 hours and i feel that is a very long time. Can i ask, what time frames others have.

 

Is it just a matter of how much product you need to hold and rework if there is a fail?? or is there a direct method that will tell you the required frequency. They appear to have no justification as to why it is every 4 hours.

 

Lastly, we have it calibrated annually and as mentioned above checked every 4 hours by the operators. should there be another internal verification/validation between calibration periods or whats the recommended practice?

 

Cheers,

Rob

Hi Rob,

It's an amazingly popular question. Many threads place the last factor in set below as the major determining factor.

Standard is unknown but, if BRC, frequency recommendation should consider -

•  start-up and nish of shifts
•  product changeovers
•  change in machine settings following downtime for repairs
•  customer requirements
•  regular checks throughout production (these should consider the site’s ability to recover and retest product in the event of a failure; therefore a minimum of hourly testing is typically expected)

 

.[despite Post 2,  I would personally have thought a minimum frequency should be once per hour ]

V.slightly off-query but also see -

https://www.ifsqn.co...ks/#entry163407

Last part of OP mixes together calibration, checking, validation and verification. Some clarification as to meaning is required. Offhand, 2nd = 4th. 3rd = sensitivity = Prelim. set-up. 1st = "arbitrary" but typically annually.

Hi Rob,

First the Metal Detector and Xray machines are externally calibrated annually;

Second, QA team validates all the Metal Detector and Xray machines annually;

Last, the line operators calibrate the MD and Xray the first thing before production starts. 

We check products every half hour. 

hope it helps.

Cheers

Donna

We run checks based on volume and what would be investigation and recovery time back to being in production again.

Our standard is every 2 hours.

Thanks every one for your replies.

The standard is FSSC 22000 which I'm new to.

I agree that at a minimum it should be hourly. Which i am going to introduce, probably with much push back from production.

Thanks again.

Further to my inquiry. When validating before production do you start product let it get to the metal detector than test the first product or just put the test piece on the conveyor belt?

Thanks in advance. 

Further to my inquiry. When validating before production do you start product let it get to the metal detector than test the first product or just put the test piece on the conveyor belt?

 

Thanks in advance. 

I assume you are referring to a normal Production run.

This is (typically) verification, not validation.

There is a "multiple" procedure involved which should be time implemented as noted Post 3. Procedure Includes axial belt positioning of test sample(s), grouping of test sample, MD rejection capability..

Hello rewel,

We are producing pasteurized crab meat and BRC certified. Our frequency of MD verification is every 30 mins. The advantage is, if the machine fail on the verification, you have only 30 mins of product that you have to recall/recheck.

Hope it could help.

regards,

redfox

Good morning,

I have a question regarding metal detector verification for food processing plants. We are testing our test pieces 3 times at the following intervals: Prior to the first use on the shift when work is being performed, Upon returning to the line when the line is shuts down for breaks/lunch, at the end of each production run or batch of material, and at the beginning of starting any new job. The updated NSF guidance document does not state to verify 3 times anymore. I am curious if you are only testing the test pieces once or 3 times each. Thank you for your help!

Good morning,

I have a question regarding metal detector verification for food processing plants. We are testing our test pieces 3 times at the following intervals: Prior to the first use on the shift when work is being performed, Upon returning to the line when the line is shuts down for breaks/lunch, at the end of each production run or batch of material, and at the beginning of starting any new job. The updated NSF guidance document does not state to verify 3 times anymore. I am curious if you are only testing the test pieces once or 3 times each. Thank you for your help!

We do once each test card.   Three times to verify a kick out is clean though.

Thank you :)

... The updated NSF guidance document does not state to verify 3 times anymore. I am curious if you are only testing the test pieces once or 3 times each. Thank you for your help!

I would say that it is still "best practice" to use multiple passes for each sample -- this reduces the likely hood of false positives or negatives.  For practicality though, and with pressure from operations to keep up-time as high as possible, a single pass for each sample is technically acceptable.

Similar things can be said for the frequency of checks, more is better, but the risk-reward benefit drops off rapidly under some circumstances.  It's all a balance around how much risk you're willing to accept for the possibility that you will have to rework or re-test everything back to the last good check if you have a failure.

Hi all,

 

New to metal detectors as I came for the beverage industry.

 

I am just after some thoughts.

 

Currently our checks on the metal detector are every 4 hours and i feel that is a very long time. Can i ask, what time frames others have.

 

Is it just a matter of how much product you need to hold and rework if there is a fail?? or is there a direct method that will tell you the required frequency. They appear to have no justification as to why it is every 4 hours.

 

Lastly, we have it calibrated annually and as mentioned above checked every 4 hours by the operators. should there be another internal verification/validation between calibration periods or whats the recommended practice?

 

Cheers,

Rob

Hi Rob,

The metal detectors which are installed on the packing conveyor are checked after every two hours.

The metal detector which are installed in the product transfer line are checked at the beginning of the shift.

Hi Rob,

The metal detectors which are installed on the packing conveyor are checked after every two hours.

The metal detector which are installed in the product transfer line are checked at the beginning of the shift.

Hi, Zameer.

Could you send or suggest the reference standard for validate or verificate this method?

Hi BayuGarin,

reference standard or regulation is unavailable. This is solely based on our risk assessment and study.

Hi, 

The Metal Detector machines are externally calibrated annually

QA team validates the Metal Detector machines annually;

Daily, by trained operatives ; 

- Reject confirmation failsafe test (start and end of every shift) 

- Bin full failsafe test (start and end of every shift) 

- Low Air test (Start and end of every shift) (if fitted) 

- Consecutive pack test (Start and end of every shift, production run & hourly) 

- Memory test (start and end of every shift) 

- 20 mm Ferrous Ball test 

;)