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Many people who have been in contact with the zinc oxide <a href="http://www.transformer-tester.com/arrester-teser/" target="_self">arrester tester</a> only know that this tester is used for electrical test and arrester testing, but the specific usage requirements and methods may not be well understood. Now the editor has compiled this article to give everyone a specific understanding of the zinc oxide arrester tester, so that everyone can use this instrument better and more conveniently to ensure the normal operation of the zinc oxide arrester.Under normal circumstances, a lightning arrester is an electrical appliance used to protect electrical equipment from high transient overvoltage hazards and to limit the freewheeling time and often limit the freewheeling amplitude. It is also another important equipment that is often used when communication cables are used to prevent lightning damage. The zinc oxide arrester tester mainly monitors the electrical performance of the arrester.
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Glove Integrity Testing – Pressure decay Method: Performance Qualification
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In recent years, Glove Integrity Testing has been profoundly discussed and numerous articles have been written on this topic. However, many doubts still remain within the industry due to the lack of norms and clear guidance available. In 2008 Annex 1 to EU Guidelines to Good Manufacturing Practice reiterated the importance of having glove integrity testing:<br style="box-sizing: border-box;"/>“25. Monitoring should be carried out routinely and should include frequent leak testing of the isolator and glove/sleeve system.”
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Over the course of the past few years different industry specific associations have conducted statistical studies about the frequency in which this type of testing is performed in the pharma industry and the results indicated that the test is executed normally prior to each batch of a production run.<br style="box-sizing: border-box;"/>However as far as performance requirements the question is still open: which hole diameter should I be able to detect?
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The theoretical answer would probably be 1μm (bacteria spores diameter), but the practical answer is much larger due to technological limitations at this time.
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The methodologies of testing available today are many, but few of them may be automated and many times they are not suitable for the routine.
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Moreover today it is difficult to find equipment to test the integrity of gloves that comes with performance qualification (PQ) and this is mainly due to the lack of test repeatability. Although there are many different methods available in the industry, the method used by the greatest portion of the users to test the integrity of the gloves is the Positive Pressure Decay method which follows the international standard ISO 14644-7 Annex E.5.
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The ISO 14644 Part 7 doesn’t detail specific methodologies for the Positive Pressure Decay. In terms of acceptance criteria many different interpretations can be reached. The box below shows what the ISO norm states about the test procedure and the results.
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As such, the equipment and the test can be easily validated while the specific glove and fixing mechanism (flange and counterflange, o-ring, etc.) is characterized in terms of “normal leakage” (Closed System curve). Before running the test, it is important that the integrity of the machine running the test is also verified and assured.
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With the method described above a variety of hole diameters can be detected developing the correct test parameters.However the detection limits are primarily influenced by the precision of the adopted transmitters, statistics involved and time constraints.
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Using this method with a calibrated hole of 100 μm a high level of reproducibility and a very, very low frequency of false positives has been observed. This means that an automatic <a href="http://www.transformer-tester.com/gloves-test-machine/" target="_self">gloves test machine</a> may be easily validated. Lower detection limits may be achieved by the use of smaller calibrated hole sizes, but this practice will impact the reproducibility and the probability of false positives.
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