标题: 关于ＩＥＣ６０３３５－１第３０．２．３中的＂２Ｓ＂ [打印本页] 作者: xltpxe 时间: 2011-11-27 14:32 标题: 关于ＩＥＣ６０３３５－１第３０．２．３中的＂２Ｓ＂ 大家有没有发觉里的＂２Ｓ＂不好解释．
我现在发觉有一些人认为是整个测试过程中持续燃烧时间不能超过两秒，有的又认为是样品离开灼热丝后持续燃烧不能超过两秒．到底是哪一个呢？
如是前者的话，那有几个样品能通过的？如不通过的话又得加做针焰测试岂不是很麻烦？作者: dotzuv 时间: 2011-11-27 14:33
Parts that withstand the glow-wire test of IEC 60695-2-11, but which, during the test, produce
a flame that persists for longer than 2 s, are further tested as follows. Parts above the
connection within the envelope of a vertical cylinder having a diameter of 20 mm and a height
of 50 mm are subjected to the needle-flame test of annex E. However, parts shielded by a
barrier that meets the needle-flame test of annex E are not tested.
The needle-flame test is not carried out on parts of material classified as V-0 or V-1 according
to IEC 60695-11-10, provided that the test sample was no thicker than the relevant part.
以上是我从30.2.3.2 of IEC60335里复制下来的内容。"but which, during the test, produce
a flame that persists for longer than 2 s, are further tested as follows."很明显，是在测试过程中的持续燃烧两秒，而不是样品离开灼热丝后燃烧两秒。作者: 生气了 时间: 2011-11-27 14:33
是前者。
首先，大家要明白为何有这个2秒的限制？这个测试是针对无人照管的器具而定，既然无人照管，火的扩散将会造成极大的危害。而火源如果持续2秒以上就意味着有扩散的危险，如果是离开灼热丝后2秒，就意味着可能是32秒，火早已扩散开来了。
如上所述，火源持结超过2秒就可能扩散，因此，标准就要求火源周围20mm直径，50mm高范围内的所有材料要经受针焰测试，其意义就在于，如果火源有进一步扩散的话，则周围的材料就要能阻止火的扩散。
下图是解释为何确定20mm直径，50mm高范围，可以想象一下打火机就清楚了。
