Guideline to Calibrate Chamber Temp. & Pressure of a Medical Steam Sterilizer

A

aramono

Hello,
It's my first post and before every thing I’m so sorry for my bad English.

I need to develop a SOP for calibration of temperature and pressure of the autoclave's chamber when machine is working (during machine working on) But I didn’t find any guideline to do this.

I read many related standard ( because in time I develop a non complete sop for validation according to EN17665) such as: EN 285, EN 13060, EN 17665, HTM2010, PDA tr no.1,

And also I can’t find the scope that I need, in some temperature calibration standard (that are specially for testing Environmental & climatic chambers) such as IEC 60068 ( I review approx. all parts) afnor nfx 15-140, dkd-r 5-7. Because all of them need to stable condition for temperature recording and also need to calibrate at atmospheric pressure.

Unfortunately the validation process that explained in these standards (EN 285, EN17665) had many critical parameters like how to measuring equilibration time, fluctuation, variances, and more item but didn’t focus how to calibration.

I need to calibrate for example 8 points of sterilizer chamber in 2 temperature points 121C and 134C, and also for pressure.
I need a guideline that explained a procedure for calibration temperature, in pressure about 3300 mbar absolute and also another one to calibration pressure, in 134C.

Thanks for your cooperation.
 
Last edited by a moderator:

harry

Trusted Information Resource
I'm still waiting for your feedback..

We are sorry, the Cove had been rather quiet because of the year end holiday season so many of those that can help you are not around. I will take a stab.

1. Don't mix-up validation with calibration. Validation is defined as the establishment of documented evidence which provides a high degree of assurance that a planned process will consistently perform according to the intended specified outcomes. The only relation as I can see is that all equipment must be calibrated first before validation is carried out.

2. With regards to calibration of autoclave, it is beyond me but you should get some information in this search: autoclave calibration
 
A

aramono

Thank you very much for your response harry,

1- According to your declaration, I believe that we need calibration before and after validation process.
If I told you regarding production and validation standards because I wanted just to inform you about references that I have already studied but didn?t find any good practice about calibration.

2- Unfortunately, problem is that I have already searched near 2 months by all kind of keywords which is related to calibration. (it drive me crazy because its first time that I can't find a stuff by searching on internet!!)
I have tested all keywords which is related to calibration temperature and pressure for Environmental, climatic, pressurized chamber/vessel that I thought.
And also all the companies which are working on validation and calibration for autoclaves, speak just about validation standards and they do not put information about calibration standard that they do their procedure accordingly.

Do you think that I should wait till the end of holiday period? Please be so kind to let me know how long does it take.

Thanks again..
 
D

dv8shane

I have calibrated a couple of sterilizer/autoclaves, it always entailed having the calibration temperature sensor in the chamber within 1 inch of the controller/recorder sensors depending which was under test, and having a T fixture inserted in the pressure line with the calibrated gauge or sensor attached. The rest is documenting the test points for standardized testing according to your process needs. It is a bit of work to set up but once done is usually easily repeatable.
 

BradM

Leader
Admin
Hopefully, as mentioned earlier, this chamber has been incorporated into a Validation Master Plan for your facility.

Hopefully you have a plan for qualification of this sterilizer prior to use; which would include establishing validated cycles. Also, you will probably have non-validated cycles and experimental cycles. There should be security levels which distinguish access to the different controls on the sterilizer; one of the highest levels being the calibration access.

Have you looked through the manual that came with the sterilizer? If this is GmP-designed sterilizer, I'm sure you paid a fair amount of money for it. It either came with a service manual; or one is available. You are probably going to need it, as it will specify how to make adjustments to the sensors.

So I would proceed in this manner:

  • Before beginning, assure you have sufficient calibration equipment to perform this activity (pressure calibrator, pressure/vacuum simulation, oil/ice baths, suitable temp. standard, etc.) That stuff can get very pricey very quickly; so if you're small, you may want to contract that service out. Assure your standards have suitable accuracy.
  • Review the functional requirements, mfg. information, and (hopefully accessible) is the initial calibration on the chamber. This information should guide you to what sensors are needed for calibration, the test points that are to be verified, and the acceptable tolerance. So using whatever method your organization has, formally identify which instruments are to be calibrated and the corresponding criteria.
  • Note: Some sensors may not have direct product impact, but can affect the proper operation of the sterilizer. You may want to assess these as a maintenance function: calibrate/adjust as needed, but no out of tolerance reporting required.
  • Find a procedure in your organization that would be similar. It may be easier to start from scratch, but at least it will initially be in the proper format.
  • Go through the sequence of steps with the person writing/executing the IQ/OQ. They have an understanding of the chamber, the valves, etc. You need to have a clear series of steps as to how to isolate steam, air, water (and where required, electrical) sources to perform this service. This may need to be accompanied with lockout/tag-out procedures.
  • Verify that there is no environmental conditions (differential pressure, particulate counts, etc.) that will be affected.
  • I would recommend proceduralizing who is to be contacted prior to calibration to assure no production is disrupted, and no sterile product is affected.
  • If available, I would write down all calibration offsets/parameters prior to calibration. That way, if something really goes wrong, you can at least have the information to return to a working state.
  • Note: I would not replicate the service manual in the procedure; rather, I would point to it where relevant. You should "control" that service manual so it doesn't disappear. Some of those manuals are extremely expensive and replacement costs are over $1,000 (USD).;)
  • Turn all utilities back on, and remove any logout/tagout identifiers that may have been used.
  • Once calibration is complete, I would run a test run to assure the chamber works properly and there are no alarms/etc. associated with the calibration you performed.
  • Assure the calibration technician cleans up the area, notes any logbook entries (for some processes,any/all run should be accounted for), and notifies the appropriate individuals as to being complete.
 
A

aramono

I really appreciate for your kind information.​

In fact I am going to establish a test and calibration laboratory only for steam autoclaves. Also, we want to get ISO17025 till next year.( Hope so!!)​

We do not have any problem regarding equipment. I use Ebro data logger EBI10 temperature and pressure data logger (8 Temperature sensor and 1 pressure sensor- according to the structural and type tests equipment of EN285 and EN13060)​

The laboratory that we founded, is a part of our company does not have any problem since we are working in sterilization field for a long time and we do the after sale service of small and big sterilizers(3 italian brands).​

As I have already told you, I found enough information in the different part of standard IEC60068 about the calibration of temperature for the climatic chamber. But the problem is: The test procedures that explained in this standard is for atmospheric pressure condition of this chambers (normal pressure).​

I want to know if there is some guideline or standards like IEC60068 or dkd-r 5-7 for calibration of temperature but in high pressure condition ( high pressure chambers)?? A standard that I could refer to it directly. A guideline that could to be used in similar conditions, even not only for autoclaves.

I know if there is not some standard or certain rule, I can use the method of normal temperature calibration and do the test . Then repeat this method and change it for standardized our procedure.​
 
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