5 Top Tips for Calibration Success
Article By Darren Jones, Director & Senior Consultant for EPiC Auditors Limited
Calibration is an often-overlooked area of the PQS; many calibration certificates are incorrect or don’t contain adequate detail and in many cases are not understood by the site experts!
Calibration services are frequently outsourced and I often find that key GMP decisions have also been inappropriately outsourced as well! Does the calibration company set the limits? Who determines how and when out of specification results are reported?
Many calibration certificates do not state Pass or Fail… Why not? The certificates often just contain the limits and the data. I regularly find calibration results that do not comply with the limits- the calculations have not been done and no one in the Pharma company has checked the data!
Limits are sometime specified as +/-2% of FSD (full scale deflection). What does this mean? Often the method of calculating this is not clear and the calculations used to determine this limit are not recorded or checked.
Given accurate instrumentation is key to achieving process control, which ultimately assures product quality, calibration requirements need to be understood and properly managed.
Tips for success:
- Use multi-point calibration over the working range of the instrument.
- Ensure you set, or at least approve the limits applied during calibration, don’t leave this just to the calibration contractor.
- Have a contract with the calibration provider that includes instruments, frequency, limits, ranges and out of specification results reporting. Appendices containing tables can be useful to manage the detailed information.
- Ensure results are reported as found and as left, i.e. pre and post any adjustment, you don’t want to miss a failed as found result.
- Ensure limits are clearly understood. The SOP should show how to calculate limits e.g. based on FSD and these calculations should be documented and checked as per any other important calculation. Evaluate the limits using Pass/Fail criteria.
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