Equipment Calibration, Verification and Maintenance Procedure

Purpose. Defines how measuring and testing equipment is identified, calibrated, verified, maintained and taken out of service so that measurement results are traceable and reliable.

1.Equipment register

Every item of equipment that affects a test result must be listed in the equipment and calibration register with a unique asset number, description, location, calibration interval, last and next calibration dates, verification schedule and status. The register is the single source of calibration status and the laboratory information system will not allow a result to be released against equipment whose status is not In service.

2.Calibration

Calibration must be traceable to national measurement standards through an accredited calibration provider or through the laboratory's own reference standards. Balances, thermometers, reference masses, volumetric glassware, compression machines and field meters are calibrated at the intervals stated in the register. Calibration certificates are attached to the register entry and reviewed by the section manager, who must record whether the results meet the method requirements before the equipment is returned to service.

3.Verification and intermediate checks

Between calibrations, staff must perform the intermediate checks specified for the equipment: daily balance checks with reference masses, daily temperature checks of incubators, ovens, fridges and curing tanks, pH meter calibration with buffers before each use, and spectrometer calibration with certified standards each run. Checks are recorded in the equipment log and any check outside the acceptance limit must be reported as a nonconformance.

• Balances: daily reference mass check
• Incubators, fridges and ovens: daily temperature record
• pH and conductivity meters: buffer calibration before use
• Instruments: calibration standards and quality control each batch
• Compression machine: monthly verification with a proving device

4.Maintenance

Planned maintenance is scheduled in the register and carried out by the manufacturer's service agent or trained staff. Maintenance records include the date, the work done, parts replaced and the verification performed before return to service. Fume cupboards and biosafety cabinets are tested annually by a certified technician.

5.Out of service

Equipment that fails a calibration or check, is overloaded, mishandled or gives suspect results must be labelled Out of service and its register status changed immediately. The section manager must assess results produced since the last satisfactory check and record the assessment as a nonconformance where results are affected. The equipment must not be used until it is repaired and verified.

6.Records

Calibration certificates, verification logs and maintenance records are retained for the life of the equipment plus five years. The Quality Manager reviews the register monthly for overdue calibrations and reports them to the quality meeting.