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引用第10楼franco于2009-05-07 20:39发表的 :
0 Y* W" z$ i/ n0 fThe oscillating member is moved backwards and forwards through an angle of 90° (45° on
+ `2 _. T/ L* e( _3 T- x9 ]: leither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per 0 _, F& [' J9 [2 Q
min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the : ?- }" J* P! X2 L9 V
sample 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。
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翻译成中文的主要意思就是:
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7 y* \6 }7 h6 o/ l( ~+ |& DThe oscillating member is moved backwards and forwards through an angle of 90° (45° on 5 q% X2 q& u& q, i0 ~- L
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
/ ]) ~' z" h- L$ O1 O( Pmin. - 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。
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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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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°。: [: L3 G1 ?# D3 u g4 @
% f% N# ~* x/ A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。# m% m; F4 x9 r
6 ?. i! I# j9 {% z& L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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8 z w; W0 J/ ]8 M; ^- 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°。
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* x% p H6 Z" H! j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:' K+ T {; A. [: X' p
6 E, v) K& [, B, i9 b8 C0 F V* MA 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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