Question 1
Link to questionDuring an audit of a medical device manufacturer\'s measurement management system, an auditor reviews the calibration records for a critical pressure gauge used in product testing. The gauge\'s specified calibration interval is 18 months. However, performance monitoring data reveals that the gauge consistently drifts beyond its acceptable tolerance of \ \\pm 0.05\ MPa at the 12-month mark. What is the most appropriate action for the auditor to recommend regarding the calibration interval for this gauge, based on the principles of ISO 10012:2003?
Recommend a reduction in the calibration interval to 12 months or less to ensure continued fitness for purpose.
Advise the organization to continue with the 18-month interval, provided a post-calibration adjustment is always performed.
Suggest that the organization document the observed drift but maintain the 18-month interval until a failure occurs.
Propose an increase in the calibration interval to 24 months, assuming the drift is within a defined acceptable range for extended periods.
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Correct answer
Recommend a reduction in the calibration interval to 12 months or less to ensure continued fitness for purpose.
The core principle being tested here is the auditor\'s responsibility in verifying the effectiveness of a measurement management system (MMS) concerning its calibration strategy, particularly when dealing with instruments that exhibit drift. ISO 10012:2003, Clause 7.3.2, mandates that calibration intervals should be reviewed and adjusted based on the actual performance of the measuring equipment. This implies that if an instrument consistently drifts beyond acceptable limits within its current calibration period, the interval is too long and needs to be shortened. The auditor\'s role is to confirm that such adjustments are made proactively, not just reactively after a failure.
Consider an instrument, a digital thermometer, used for critical temperature monitoring in a pharmaceutical manufacturing process. The established calibration interval is 12 months. During routine checks, it\'s observed that the thermometer exhibits a drift of \0.5^\\circ C\ in the positive direction every 3 months, consistently exceeding the acceptable tolerance of \ \\pm 0.3^\\circ C\ by the 6-month mark. This indicates a pattern of instability. An auditor, reviewing the calibration records and performance data, would look for evidence that the organization has analyzed this drift pattern and adjusted the calibration frequency accordingly. The most appropriate action, based on the observed drift exceeding tolerance within half the calibration period, would be to reduce the calibration interval to 6 months or even less, to ensure measurements remain within acceptable uncertainty limits throughout the period. The auditor would verify that the organization has a documented process for this review and has implemented the necessary corrective action by shortening the interval. This proactive approach aligns with the standard\'s emphasis on ensuring the fitness for purpose of measuring equipment.
