高效过滤器泄漏率测试：≤0.01%是否必须

1、高效过滤器泄漏率测试：0.01%是否必须What is the Acceptance Criteria of HEPA?acceptance criteria什么是高效过滤器的接受标准？acceptance criteriaultimately determined by thetest leak size limit of greaterThe approach most test standards take regarding ultimately determined by thetest leak size limit of greatercustomerand supplier.

2、However, a scan than or equal to0.01% has generally been adopted for many applications utilizing HEPA flters orclean areas of varying classifcations.Although the 0.01% leak size has beenused historically and has its origins linked to early generation analog photometertest equipment, establishing a l

3、eak size limit of 0.01% as an acceptancecriteria without performing a science and risk-based assessment can result inissuesrelating to leak testing and can contribute to signifcantoperationalcosts if an out of tolerance or failed condition is identifed ina low riskarea. As previouslynoted in Section

4、 6.5, flters are not 100%efcient and areexpected to have some naturalor integral penetrationof particles near theMPPS. Test acceptance limits become more controversial or problematic whenutilizing lower-rated HEPA flters where the acceptable factory penetration ator near MPPS can be comparable to or

5、 larger than the feldtest leak sizeacceptance criteria.This is especially true where the bleed through e ?ectcan occur (seeSection 6.9).When purchasing a flter, it is thereforeimportant toconsider a flter s rating as well as how it will be tested afterinstallationin order to avoid unnecessary feld t

6、est failures.大多数测试标准关于高效过滤器泄漏率的接受标准是，可接受的泄漏限度最终由客户和供应商共同确定。但是，对于使用HEPA过滤器或不同级别洁净区的许多应用，大多数采用0 0.01 %的扫描测试泄漏标准。尽管0.01 %的泄漏率在历史上已经使用过，并且其起源与早期的模拟光度计测试设备相关联，但在没有进行科学和基于风险的评估的情况下，将0.01 %的泄漏率标准作为可接受标准将导致与泄漏测试有关的问题，并且如果在低风险区域发现超限或失败情况，将可能会带来巨大的运营成本。过滤器不是100 %截留的，并且预计 MPPS附近的粒子在过滤器局部或整体可以穿透。当使用较低级别的HEPA过滤器

7、时,工厂进行的 MPPS或MPPS附近粒子的可接受泄漏率标准可能等于或大于现 场泄漏率测试的接受标准，测试接受标准会变得更具争议和困难。在可能发生 泄漏的地方尤其如此。因此，在购买过滤器时，考虑过滤器的等级以及安装后 如何进行测试非常重要，以避免不必要的现场测试失败。ISO 14644-333 gives guidance on how alternative leakacceptancecriteria can be implemented. In a risk-based approach, it may be ideal to haveacceptance criteria that t

8、rends with the eficiency of the flters being used orthecleanliness of the room being tested. ISO 14644-3 uses the factory flter efciency rating as the basis of acceptancecriteria negotiation. The leak acceptancecriteria for a photometer leak test and a particle counter based leaktestshould be the sa

9、me, as the theory and methodology behind leak sizing isidenticalfor both methods.If performedproperly,a leak test withfor both methods.If performedproperly,a leak test withphotometeranda particle counter will result in the same leak size (Meek, et al., 2011121).photometerandISO 14644-333提供了有关如何实施泄漏替

10、代标准的指南。在基于风险的方法中，理想的接受标准是，该接受标准可以反映所使用过滤器的效率或所测试房间的洁净度。ISO 14644-3 使用工厂过滤效率等级作为接受标准协商的基础。光度计泄漏测试和基于粒子计数器的泄漏测试的泄漏接受标准应该相同，因为两种方法背后的理论和方法是相同的。如果执行得当，使用光度计和粒子计数器进行的泄漏测试将得到相同的泄漏率结果(Meek等，2011 121)A leak detected in excess of 0,01 % of the upstream massconcentration is deemed to exceed themaximum allowab

11、le penetration. However,for filter systems of an integral efficiency at MPPS 99,95 %and less than99,995 %, theacceptance criterion is 0,1 %.如果检测到的泄漏量超过上游浓度的0.01 %, 一般认为该泄漏率超过最大允许标准。但是，对于整体效率 MPPS为99.95 %且小于99,995 %的过滤器系统（如H13过滤器），接受标准为0.1%。If filter systems of an integral efficiency lower than 99,95

12、 %at MPPS are to be tested, a different acceptance criterion are necessary, basedon agreement between customer and supplier.如果要测试MPPS整体效率低于99.95%的过滤系统，则根据客户和供应商之间的协议，需要不一样的接受标准。The flters for depyrogenation tunnel用于去热原隧道的高效过滤器The flters ftted to a depyrogenation tunnel are subject toprolongedperiods

13、 of high temperature operation, so standard flters are notsuitable. Special flters rated to 350 C are available with a manufacturerguarantee d efciency of 99.99% for 0.3(i m particles (notethat the FDA defnitionof a HEPA is 99.97% at 0.3 m) at a temperature of 350 C) with a ceramicmaterial used for

14、the media to frame seal. Recently there have been advances inthe materials available and ?exible sealants are being introduced that canreduce the heat up time and reduce the risk of sealant cracking. Traditionalflters need to have a controlled heat up and cool down time (typically not toexceed 1C pe

15、r minute; the rate shouldbe confrmedwith the flter supplier)toprevent heat stress damageto the seals. Often the systems aremaintained hotduring periods of non-use to reduce the heat cycling on the flter.安装到去热原隧道中的过滤器需要经受长时间的高温操作，因此不适用标准过滤器。厂家使用陶瓷材料用于滤材与边框的密封可提供耐受350 C的对0.3颗粒的效率为 99.99 %的特殊过滤器(注， FDA

16、对HEPA的定义为 99.97 % 0.3 m m)。最近，可用的材料有了进步，并且引入了柔性密封剂，可以减少 加热时间并降低密封剂开裂的风险。传统的过滤器需要具有受控的加热和冷却速度(通常不超过1 C/分钟；应与过滤器供应商确认该速率)，以防止热应力 损坏密封件。通常，在不使用期间，系统会保持高温，以减少过滤器的加热循Filters used for depyrogenation tunnel are generally H14. Theseflters canbe full facescan leak testedoninstallation,but aftertheinitialheat

17、ing cycle (burning in the flter, which usually results in the fltergradebecoming equivalent toH13) traditionaltesting isnotrecommended. The oilaerosol (if it is Polyalphaolefn (PAO) will load onto the flter and burn o ? ,giving o ? unhealthy fumes, and may load the flter media; this is usually more fragileafter burn in as the binder holding the media together has o ?-gassed.DEHS (Di