Calibration and Performance Qualification Testing of Autoclaves.doc10/07/2006 What is calibration? Calibration is the process of determining the actual*temperature inside an autoclave when a given temperature is set.* Where actualђ means best estimateђ. See Uncertaintiesexplainedђbelow. So why bother? Well, without a calibration even with its uncertainties, the actual temperature inside theautoclave is unknown. The electronics may be wrong, the temperature probe may be damaged, the pressure gauge ֖ a very useful backup - may also be wrong etc. - Is it worth the risk if the process is not sterilising properly? - Is it worth the risk, in this litigious world, if the autoclave is not covered by a calibration?Calibrating, particularly if a UKAS* calibration laboratory is employed provides a powerfuldemonstration, in a court of law, that due diligence has been properly exercised. It showsthatall reasonable careђ has been taken. * UKAS is the United Kingdom Accreditation Service. They are the sole organisationrecognised by the UK government to assess calibration laboratories against international criteria.(go to www.ukas.org for more details.) What does it involve? The calibration engineer will insert a calibrated probe into an autoclave and run it at a settemperature, taking sufficient readings to produce a calibration certificate. The actualprocedures used will vary from company to company but all UKAS accredited calibrationlaboratories will work to approved procedures. The data is then used to produce a calibrationcertificate. The engineer may also attach seals to prevent access to areas that allow thecalibration to be altered. Adjustment. Calibration does not always include adjustment of the autoclave controls. Often themanufacturers control software is not accessible to untrained, third party engineers, forobvious reasons. If the autoclave cannot be adjusted and is significantly out, then the settemperature can be adjusted to compensate the difference by using the data on thecalibration certificate. If for any reason adjustment of an autoclave is not required the serviceengineer should be informed - preferably beforehand. What does it cost? This depends. The largest cost in the calibration is often getting the engineer to and from thesite. Once on site the work is generally straightforward, if rigorously controlled. It thereforemakes financial sense to choose a calibration company that has local engineers and is alsoUKAS accredited for the calibration. Calibration can also be performed as part of a routine service visit at agreed intervals. This is often an economical solution. Performance qualification. This is one of several generic terms for testing an autoclave - and its load - to ensure the loadis properly processed. Usually a calibrated, multi channel, data logger is employed for themeasurement so that considerable numbers of points in the load, together with salient pointson the autoclave, can be logged. Analysis of these results can point to many problems in thesetup of the autoclave or in the way the load is contained. Significant differences can be >

Calibration and Performance Qualification Testing of Autoclaves.doc10/07/2006 seen, for instance, between glass and plastic bottles or plastic and metal discard containers,or between single and double bagged discard loads.Performance qualification is the only way to know what is actually happening to the load.It is vital that the test load is typical of loads actually processed as the results cannotnecessarily be read across. A good calibration laboratory will consider and discuss thesefactors with the customer prior to their engineer arriving. However, once the performance qualification is done,...