Calibration & Control of Measuring and Monitoring Devices Procedure

Define the measurement requirement before equipment is relied on

Technical / Quality Management establishes the measurement performance needed for each intended use and approves the checking, adjustment and calibration requirements. The procedure requires suitable accuracy and, where relevant, precision or repeatability, with clear acceptance criteria for deciding whether a device is suitable for use, requires adjustment or must remain out of use.

Checking frequencies, and separate adjustment frequencies where applicable, are established through documented risk assessment. The assessment considers the consequence of an incorrect result, frequency and conditions of use, performance history and available manufacturer or calibration recommendations. Approved methods must either be linked to a recognised national or international measurement standard or use a recorded alternative capable of demonstrating the required measurement performance.

Keep every in-scope device identifiable, current and controlled

Measuring equipment is brought within the procedure where its results are relied on for CCP monitoring or product safety, legality or quality. Each device is linked through permanent identification to an Engineering-maintained asset register and a Technical / Quality Management-controlled calibration schedule that records the applicable use, status information and calibration due date.

The control extends to new, replacement and relocated equipment. Before an in-scope measurement is performed, the applicable asset information, calibration-schedule information and calibration status must be complete. Where a device is assigned to a different measurement use, or the measurement requirement changes, Technical / Quality Management reviews the monitoring and calibration requirements before the schedule is updated.

Protect measurement integrity during use

The procedure limits equipment use to its approved measurement purpose while identity and calibration status can be confirmed, required protection and adjustment restrictions remain intact, the display or other measurement indication is readable, and no known condition undermines confidence in the result.

Access to settings capable of affecting measurement is restricted to authorised Engineering personnel or an approved external calibration provider where the device requirements permit this. Damage, deterioration, misuse and unauthorised adjustment are controlled during use, movement and storage. A device whose condition or calibration status gives reason to doubt its measurements is taken out of use until its status has been resolved.

Use checking, calibration and adjustment to control return to service

Routine checks are performed by Quality Assurance Technicians using the approved method and acceptance criteria, while Engineering personnel coordinate internal or external calibration and carry out authorised internal adjustments. Missed, overdue or unverifiable checks or calibrations require the device to be removed from use until acceptable status is demonstrated.

After adjustment, repair, adverse calibration or technical assessment, return to use depends on acceptable checking or calibration evidence and confirmation by Technical / Quality Management that the approved acceptance criteria have been met. Calibration evidence is reviewed against the correct device, required accuracy, applicable standard linkage, available as-found or as-left results, qualifications and the next due date. Equipment that cannot meet the approved criteria remains out of use for that measurement.

Control reference equipment and critical-limit measurement

Reference equipment used to check or calibrate other devices is uniquely identified, included in the asset register and calibration schedule, and calibrated with evidence of linkage to a recognised national or international measurement standard. It is removed from use where its calibration is overdue, adverse or unverifiable, or where the required linkage cannot be confirmed.

Where an adverse reference-equipment result may have affected earlier checks or calibrations, Technical / Quality Management identifies the devices concerned and requires any device whose status cannot be demonstrated to be removed from use and checked or calibrated.

For equipment used to assess a critical limit, Technical / Quality Management considers calibration uncertainty and records the resulting suitability decision. The assessment addresses whether the device can reliably show that the approved critical limit has been achieved and is reviewed when the device, calibration uncertainty, critical limit or validated monitoring arrangement changes. Equipment is not used for critical-limit assessment where reliable determination cannot be demonstrated.

Assess previous measurements and affected product when equipment is unreliable

The procedure contains a defined response where a prescribed device is outside its specified limits, inaccurate or of uncertain calibration status. Use stops and Technical / Quality Management determines the last satisfactory check, the period during which results may have been unreliable and the product potentially affected. Production / Operations personnel identify the potentially affected product, place it on hold and prevent movement or release pending assessment.

Food-safety and product-legality effects are assessed separately. Where product safety or legality depends on results from inaccurate equipment, the at-risk product is not offered for sale. If affected product cannot be identified with certainty, all product that may have been monitored using the unreliable device remains on hold pending assessment.

Where unreliable equipment was used for CCP monitoring, the condition is treated as a CCP deviation: the affected period is determined from the last satisfactory monitoring result, potentially affected product is held, and monitoring does not resume until the equipment has been confirmed fit for use. Subsequent corrective action is managed through the HACCP corrective-action procedure. Product that has moved beyond the site’s direct control is assessed through the incident, withdrawal and recall procedure.

Defined responsibilities and evidence across the control system

Responsibility is distributed across the functions that own, maintain, use and assess measuring equipment. Senior Management provides the necessary resources and organisational arrangements. Technical / Quality Management owns the calibration-control requirements, approves performance criteria and methods, reviews evidence and determines escalation and return-to-use status. Engineering maintains the asset register, coordinates calibration and performs authorised adjustment or restoration, while Quality Assurance Technicians perform and record routine checks.

Production / Operations personnel use equipment within its approved purpose and status conditions, maintain protection controls and place potentially affected product on hold where unreliable equipment may have been used. All employees are required to stop using and report equipment that is damaged, unreadable, misused, incorrectly adjusted or of uncertain calibration status.

The evidence base includes the asset register, calibration schedule, risk assessments supporting frequencies, checking and adjustment records, calibration certificates and reviews, calibration-uncertainty assessments, equipment-failure and technical-assessment records, return-to-use confirmation and affected-product assessments. These records connect equipment status with the decisions made when measurement reliability is challenged.

A calibration-control procedure within the wider FSQMS

Within the Food Industry Hub FSQMS Policies and Procedures Suite, this procedure provides the calibration and measurement-status controls that support CCP monitoring and critical-limit decisions, product inspection and quantity control. It also defines the point at which unreliable measurement interfaces with non-conforming product control, corrective and preventive action, HACCP corrective action, and incident, withdrawal and recall assessment.

Equipment selection, commissioning and acceptance, repair methods, CCP monitoring design, critical-limit establishment and authorised product disposition remain governed by their respective procedures. That boundary keeps the Calibration & Control of Measuring and Monitoring Devices Procedure focused on measurement performance, equipment status, evidence and the response to unreliable results.