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引用第10楼franco于2009-05-07 20:39发表的 :
! s& ?1 q- H0 n+ B& s* wThe oscillating member is moved backwards and forwards through an angle of 90° (45° on ; u. @- w/ G% Y' Y
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
6 U8 J- ^/ C5 u1 Smin. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the & G; e6 L* { r% T
sample is turned through 90° about the centre line of the cord guard.
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' P7 X+ o" ~; U( ]....... 是的,这段话写的确实很明白,但是我估计你还是理解错了。
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7 }8 |: a1 F- w" j4 N4 i! f翻译成中文的主要意思就是:& A: d& ?+ z3 b+ X8 P5 d$ Q
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The oscillating member is moved backwards and forwards through an angle of 90° (45° on / ^' j* e) _# R1 ]+ z: Q# q
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per : w' y8 |+ i' q* J
min. - 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。4 t( T) Q1 g* q0 a3 O: S
1 V! W$ A: Q% r: a: b* q) ~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。! B' q3 h% M, c3 I0 i; y4 L
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After 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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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。' k# a( u. y- ~7 C- W, g& L* K
1 ]& V% N/ ^: g0 g5 a+ Z0 l4 |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。
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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°。
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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:+ n* T! E: {, T. O% D: A
* a7 H' x; I7 \' F+ w$ `: uA 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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