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发表于 2009-5-8 15:06
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引用第10楼franco于2009-05-07 20:39发表的 :
* b! X' Z3 @0 ZThe oscillating member is moved backwards and forwards through an angle of 90° (45° on
$ B4 U" y7 [7 G+ Oeither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
/ j- [. b3 R, c" t F/ mmin. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
/ L/ J3 b1 P$ fsample is turned through 90° about the centre line of the cord guard.
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....... 是的,这段话写的确实很明白,但是我估计你还是理解错了。& M7 J5 r9 H% _! q$ m' j. J$ \. F
: }4 z; s9 Y3 {& p4 E9 c% W翻译成中文的主要意思就是:' F! K. U/ Z7 P Q8 N$ V7 Z0 }+ ?8 ?
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The oscillating member is moved backwards and forwards through an angle of 90° (45° on 4 X5 |, J, F5 n2 o
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
1 d" o$ }! m) k2 ?& dmin. - 摇摆装置能够在90°的范围内前后摆动(其中这个90°指的是沿垂直位置两边各45°),以每分钟60次的频率摇摆20000次。" @( ]$ e+ U; q: u* X* w
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这句话讨论的是仪器的摆动机构要满足的特性,就是要能在90°的范围内前后摆动,如果只能在45°的范围内摆动的话,这个设备就是不符合要求的。这句话并没有涉及到一个摆动周期如何定义啊。
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4 i2 C1 } }& tAfter 10 000 flexings, the sample is turned through 90° about the centre line of the cord guard. - 10000次摆动之后,将样品沿着电线防护套的中心线转动90°。
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. E4 a( u; \0 k$ W h! T, f* d这句话说的是总共20000次的摆动样品应该在两个位置分两次完成而已,同样没有涉及到摆动周期的解释和说明。, g! s c1 G- ]" i( T
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最重要的一句话应该是:A flexing is one movement, either backwards or forwards. - 一次摇摆就是一次移动,无论是向后还是向前的。. Z5 r4 Y* o O9 i
" }* _1 K( s; @1 t这句话虽然容易引起歧义,但是仔细考虑一下也不是很难理解。可以看出,1个摆动周期就是单次的向前或者向后的移动。摇摆机构是在总共90°范围内摆动,那不管是向前还是向后的摆动角度都是45°了。由此可以得出1个摇摆周期就是45°而不是我们通常认为的90°。- v) q9 b. y/ j1 s. j& O
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摘抄UL 745-1标准中的相关章节如下,关于这个问题解释的非常清楚,供大家参考参考:& u, P0 j8 u' r. a% ^
+ b& P2 a3 E" B3 R( Y$ Q& V* Z# p# vA flexing is one movement, either backwards or forwards. That is, from vertical to 45° in one direction is the first flex, from there back to vertical is the second flex, from vertical to the opposite 45° is the third flex, from there back to vertical is the fourth flex, continuing until 10000 flexes have occurred. |
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