Calibration requirements for Metal Detectors
Hi,
Refer to metal detector topic, I've a questions.
- How frequent we need to calibrate the metal detector? I've a letter from manufacturer stated that our model of metal detector does not need calibration. However, auditor asking us to set calibration time.
- How do we calibrate our metal detector?
Hi,
Refer to metal detector topic, I've a questions.
- How frequent we need to calibrate the metal detector? I've a letter from manufacturer stated that our model of metal detector does not need calibration. However, auditor asking us to set calibration time.
- How do we calibrate our metal detector?
Hi req-sad,
"Calibration" has various interpretations, notably (1) detection capability validation, (2) routine machine overhaul/check-up
Please clarify what you/your auditor are referring to, eg Standard / clause ?
hello,
Metal Detector must be calibrated at least annually by third party calibrator which is ISO 17025 certified.
In-house testing of sensitivity to test piece must be done on site's set frequency.
regards,
redfox
Hi,
Refer to metal detector topic, I've a questions.
- How frequent we need to calibrate the metal detector? I've a letter from manufacturer stated that our model of metal detector does not need calibration. However, auditor asking us to set calibration time.
- How do we calibrate our metal detector?
hi,
You should prepare the annual calibration plan Both In-House and External Agency and it must be calibrated by NABL accredited External agency [Third Party].
In-house testing of sensitivity to test piece must be calibrated on daily basis . There is no standard available for set the frequency .
regards,
V.Sivachandran
Hi All
i deduce Posts 3,4 both referred to option (2) of Post 2.
For BRC i identified "calibration" to (1), all done in-house, no further details ever requested by auditors. Any change in (2) would prompt (1).
(As per the Engineer's Law - If it ain't broke, don't fix it).
Over to the OP as to his specific interest
In all of my metal detection experience the term "calibration" is a bit of a misnomer in this specific context. There is no actual calibration with any metal detector that you would need a technician for. You are in fact calibrating it when setting it up to detect the metal test samples. The samples are the control and the adjustment in sensitivity is your calibration to those samples.
What your auditor is really looking for is a third party verification from a factory authorized technician that certifies that the metal detector system is capable of reliably detecting the required test samples and at what settings it was tested at. Also, that there are no underlying maintenance issues that could affect the overall performance of the system.
The frequency of the certification services should be based on your own plan, or your customers requirements. From the factory point of view it is usually recommended to be done on an annual or semi-annual basis.
I hope this helps.
Eric
Hi Eric,
Thks for yr input and Welcome to the Forum ! :welcome:.
May i enquire as to which Food Standards yr comments relate to ?
Hi Charles,
Thanks for the welcome.
My comments are more general and aren't specific to any individual standard. But, I would think it relates to all of them.
In my experience, I was the one issuing the certifications on the metal detectors so that my customers were able to satisfy their auditor requirements. Although, there were a few instances where an auditor would look for something different, to my knowledge the certification was able to satisfy all standards.
Eric
Hello Charles,
Though in BRC (we are BRC certified site) no specific calibration frequency requirement for MD. But since our Metal Detecting step is a CCP the auditor required us for calibration once a year. Then our government agency which issue HACCP certification also requires us at least annually of calibration frequency on top of our every 30 minutes of specimen testing.
regards,
redfox
Hello Charles,
Though in BRC (we are BRC certified site) no specific calibration frequency requirement for MD. But since our Metal Detecting step is a CCP the auditor required us for calibration once a year. Then our government agency which issue HACCP certification also requires us at least annually of calibration frequency on top of our every 30 minutes of specimen testing.
regards,
redfox
Hi redfox,
Just to avoid confusion, can you explain what activity(s) is/are actually involved when you refer to "calibration" ?
I am guessing you mean a sequence of checking, for Ferrous/non-Ferrous/SS composition, the smallest diameter test strips which are detected by the MD ? In other words the exercise to determine the Critical Limit is equivalent to Calibration.
This is not quite the same, i think, as the activity described in 1st paragraph, Post 6, since in above procedure no changes are made/envisaged to the MD instrument settings. (in some MD manuals such changes can, I think, also be user-made to optimise sensitivity for different food martices. This could also be described as "Calibration" but would presumably also be included as a part of a, maybe annual, "maintenance" check performed typically by a local MD representative)
I have a suspicion that we are all talking at cross-purposes. :smile:
PS - I guess yr 30min. reference is regarding the interval (not actually a frequency) during a process for checking that the MD test piece(s) defined in the critical limit can be adequately detected. i call this Validation of the critical limit/MD but I daresay opinions vary.
Hello Charles,
Though in BRC (we are BRC certified site) no specific calibration frequency requirement for MD. But since our Metal Detecting step is a CCP the auditor required us for calibration once a year. Then our government agency which issue HACCP certification also requires us at least annually of calibration frequency on top of our every 30 minutes of specimen testing.
regards,
redfox
Just thinking outside the box here, but would an annual service of the MD by either the manufacturer or equivalent tick the box? Even though they (more than likely) won't be making any changes to the machine, they will be verifying that it is performing to standard. Plus, that way you're covering both the calibration and routine maintenance requirements :gleam:
Hi All,
Calibration of metal detectors is a really popular topic !.
Just as an example (the OP left it open) – here are the relevant BRC requirements –
6.4.1
The site shall identify and control measuring equipment used to monitor critical control points, product
safety and legality. This shall include as a minimum:
• a documented list of equipment and its location
• an identification code and calibration due date
• prevention from adjustment by unauthorised staff
• protection from damage, deterioration or misuse.
Here is BRC’s (Generic) definition of Calibration –
Calibration
A set of operations that establish, under specified conditions, the relationship between values of
quantities indicated by a measuring instrument or measuring system, or values represented by a
material measure or reference material, and the corresponding values realised by standards.
So how should one define “Calibration” in the context of a Metal Detector and its Specific User ?
Searching yielded 4 interpretations of MD “Calibration” –
(1) Services Companies offering a Package approach with specific "Calibration" Procedure undefined, eg –
Company 1 MD Calibration.pdf 159.11KB 454 downloads
Company 2 MD Calibration.pdf 21.92KB 306 downloads
(2) Multiple Calibrations
One User using 2 Calibrations + Regular Maintenance (!!) ( Detailed Daily own test sample / 6-month manufacturer Package (Procedure unstated)/Annual maintenance)
Dual MD Calibrations.pdf 468.33KB 270 downloads
(3) Daily Calibration with test samples
MD Daily Calibration.pdf 290.93KB 276 downloads
You-tube -
https://www.youtube....h?v=nuPaKXgxeco
https://www.youtube....h?v=Y0ZAOg4PCnI
(may now be blocked, 200919)
[Both still working 11th May,2023, Charles.C]
(4) No Calibration
tesco - Metal Detector Calibration.pdf 29.58KB 307 downloads
And from previous forum threads (among many) –
http://www.ifsqn.com...s-it-necessary/
2012
http://www.ifsqn.com...ctors-accepted/
2013
http://www.ifsqn.com...etal-detectors/
2014
Perhaps you can take your pick as far as “Calibration” is concerned although route (3) is presumably the financial winner as long as no auditor rumblings (I reserve Preventive Maintenance as a separate topic in its own right).
addendum
Unfortunately not sure where the quote originally occurs but this may explain the entry in category 4 -
According to the BRC, metal detectors cannot be calibrated technically but the sensitivity is optimized. The sensitivity can then be verified using standard sized rods or balls of different types of metals to ensure the metal detector detects these. Further validation of the metal detector by controlled spiking of the product is also
essential.
metal detection, 2010.pdf 126.35KB 338 downloads
Hello Charles,
Actually we still waiting the "calibrator" to come to our site this coming November. It is the first that the calibrator would calibrate our MD since BRC auditor required us and the local HACCP certification. As Eric says, it might be a certification from a competent authority that auditors want to see. As our experience when the machine failed to detect the test piece we adjust the sensitivity to that specific kind of metal and size. I think that already a calibration. Like other measuring device, weight and temperature, though we have in-house calibration, still the auditors are still looking for the 3rd party calibration certificate. We have to follow what auditors are looking to avoid NC.
regards,
redfox
Hi redfox,
May I suggest the appropriate challenge is "Show me the word "external" !"
PS - is this the same auditor who demanded you show him/her a original hard version of the BRC Standard ?
Really thanks for your reply. I think what my auditor need is certification from a competent authority (external calibrator). Even we do routinely checking everyday on our MD.
Ya like what redfox said "We have to follow what auditors are looking to avoid NC" :gleam: .
Really thanks for your reply. I think what my auditor need is certification from a competent authority (external calibrator). Even we do routinely checking everyday on our MD.
Ya like what redfox said "We have to follow what auditors are looking to avoid NC" :gleam: .
Hi req-sad,
I appreciate that people generally prefer to avoid confrontations. It is also worth remembering that BRC audits/CBs are themselves audited for "consistency" by their Accreditation Board.
It would be interesting to know what the BRC Interpretation Guidelines recommend "to demonstrate that measuring equipment is sufficiently accurate and reliable to provide confidence in measurement results".
Hello,
Does anyone knows if the annual calibration must be carried out with product (and metal pieces) or the product is not necessary and using only metal pieces is enough?
Please, take into consideration that I refer to the annual calibration.
Hello,
Does anyone knows if the annual calibration must be carried out with product (and metal pieces) or the product is not necessary and using only metal pieces is enough?
Please, take into consideration that I refer to the annual calibration.
4-year old thread.
I suggest to refer to Post 12
With respect to "sensitivity" it will usually vary with the food matrix.
afaik, unless stated otherwise, MD literature data typically assumes the test piece is directly passed through the MD.
For example -
metal_detection_guide.pdf 1.51MB 145 downloads
(Pg 13/32)