Sch 10 para 50
Where necessary to ensure valid results, the organisation must have procedures to ensure that its measuring equipment is— (a) calibrated or verified at specified intervals, or prior to use, against international, national or industrial measurement standards; where no such standards exist, the basis used for calibration or verification must be recorded; (b) adjusted or re-adjusted as necessary; (c) identified to enable the calibration status to be determined; (d) safeguarded from adjustments that would invalidate the measurement result; (e) protected from damage and deterioration during handling, maintenance and storage.