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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 :+ ]' }0 i0 {$ t+ n, i$ u3 t' S' \
The oscillating member is moved backwards and forwards through an angle of 90° (45° on $ W" D4 k& m4 V/ ~- [
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per O5 D8 H- i, L9 W1 K
min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
6 f0 M* i0 C( R |sample is turned through 90° about the centre line of the cord guard. . b2 Y1 t' T' J7 Q
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翻译成中文的主要意思就是：
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9 i8 v8 V/ E) g7 N& C% UThe oscillating member is moved backwards and forwards through an angle of 90° (45° on : C3 e7 k* g$ E( _
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
2 K7 h/ Z& g; }' Xmin. - 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。. E2 G; P$ S' h( j9 q/ C2 `. E6 j, c
. Z$ ?. E9 b2 Q- p( Q8 V) r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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1 _" Z- N3 G. z i$ U2 b+ g' d! \9 cAfter 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°。* `2 T5 v6 s7 g8 r( q
% k3 R- y8 Z2 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。
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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。
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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：" I7 u2 x1 E5 A D4 S2 j
% z- l: O' I% T8 dA 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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发表于 2009-5-7 20:39
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