Calibration of metal detectors is a really popular topic !.
Just as an example (the OP left it open) – here are the relevant BRC requirements –
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 definition of 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
Company 2 MD Calibration.pdf 21.92KB
(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
(3) Daily Calibration with test samples
MD Daily Calibration.pdf 290.93KB
(may now be blocked, 200919)
(4) No Calibration
tesco - Metal Detector Calibration.pdf 29.58KB
And from previous forum threads (among many) –
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).
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
metal detection, 2010.pdf 126.35KB
Edited by Charles.C, 20 September 2019 - 05:07 AM.
added comment to (3)