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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 :6 d- e& v' i9 k: T( U" p5 r& `
The oscillating member is moved backwards and forwards through an angle of 90° (45° on
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min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the 0 C: Z& g' }8 J7 P
sample is turned through 90° about the centre line of the cord guard. " J6 L+ ]1 G5 ~; e3 L2 v# r
* X) |& R8 c4 P....... 是的,这段话写的确实很明白,但是我估计你还是理解错了。6 T, d7 g! w6 }& P
, Y0 O, h' l8 B( l( \6 H, G翻译成中文的主要意思就是:
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The oscillating member is moved backwards and forwards through an angle of 90° (45° on - K, L ]% i( }
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per 6 a9 c' f$ z3 Z' N ^" h
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。! k7 Y0 B9 c- n* D& O7 h
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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。; d, d8 n2 k! }" r
; w3 o$ X+ k+ K+ jAfter 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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/ G ^ h3 \. C' J4 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。+ S- t0 L5 Z1 J h) u
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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°。7 m% U/ P9 v# I! A3 M
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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:' b$ ]1 ?6 k; n; Z0 a1 n
# q: E9 F- E \2 I" ~. qA 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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