Problem & answerM-01
Metal Detector Fails Challenge Test
Also covers: Critical control point
Likely causes
- Sensitivity drift
- Wrong product setting
- Test piece passed off-centre or at the wrong speed
- Belt or aperture changed after maintenance
- Genuine contamination
How to fix it
- 1Stop the line immediately; no further product past the detector.
- 2Isolate all product since the last successful challenge test in labelled quarantine.
- 3Re-run the challenge with ferrous, non-ferrous and stainless steel test pieces at the specified size, passed in normal product orientation, centrally and at line speed.
- 4If it fails again: check the product setting, test piece position, and any recent maintenance, cleaning or belt changes. Only trained and authorised staff may change sensitivity.
- 5If it passes on re-test, document the event anyway.
- 6Notify QA in every case; QA decides on the quarantined product.
- 7Restart only after a documented passing challenge test and QA sign-off.
- 8Complete the monitoring record: time, result, action and who was notified.
It is fixed when
All three test pieces detected and rejected; QA sign-off.
Stop it coming back
- Challenge test at start-up, at set intervals, after stops or adjustments and at batch end.
Did this solve the problem?