Initial Autoclave PQ


I am performing an intial PQ for a new autoclave. I have a lot of loads to qualify and was wondering what the general rule is when it comes to calibration verification. How many runs can I perform before I have to perform a post calibration verification / re-calibrate the TCs. Any insight will be helpful.


It depends to you! There are no requirements, but if you perform cal verification after many runs and if it fails then your tests are under investigation too. To save time but to be sure that your tests are ok perform quick check after every3rd test run (put TCs on the referent temperature at 121oC) and perform verification after every 6 runs

I would like to share my understanding of he calibration/ verifications requirements and hoping that would help to make a decision.

  1. From a technical stand point (especially if you are using Kaye for qualification), verification is just the measure to evaluate the differences with respect to original offsets that were set during calibration (by the equipment). That means it will provide assurance that runs between are good and valid.

  2. I suggestion is that every three runs, calibration certification (three points please as there are lot of questions around it) and every 6 runs calibration to account for offsets due to physical and thermal shock thermocouples are going through during steaming cycle and in practice, though it is little conservative approach, will provide assurance with lower risk.

  3. I would rather spend hour and half (for most cases) to perform calibration and verifications compared to take a risk of wasting steam, resources, project time, microbiology testing time and writing deviation and ofcourse explaining them. Just my thoughts.

Hope this helps!

There is no “rule” about calibration verification. It is a risk balance. You can go 20 (or more runs) between verifications. This is quicker, but the downside is that if the verification fails, then you might have to throw out 20 runs and start over. So you save a little time (by stretching out the verification) but you waste a ton of time by having to redo the 20 runs.

I agree with Graham or joksavs, that 3 or 6 seems appropriate.