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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 :
4 E8 L; b. G$ G6 UThe oscillating member is moved backwards and forwards through an angle of 90° (45° on
- X; }; C+ G7 ceither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per # z6 p& {, }, s L; p" N
min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
9 h' O. T' V8 ~4 f% c# Z4 G$ v- T: L- isample is turned through 90° about the centre line of the cord guard. ! X2 e1 v0 [+ h: b g
5 m9 ^" N) y: C....... 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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4 {8 y; n& V4 z: F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 7 j: q5 [1 K& O" \8 X" v6 \
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per ; Z0 ?# x7 q0 c7 Q6 P/ t& t
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。8 |8 k( R/ T& @" b! ?
' I# | |" E w H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。& b8 Y) s9 R9 K7 F
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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°。3 f( k+ V( Q2 d. m; f6 a$ h
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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。% f) V8 u. @" L
3 Q* a" }% C6 r. |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。, k3 l- x- R' V- p
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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°。" O, q# b7 u3 B6 h0 ]
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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:
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A 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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