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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 :+ x9 o! g7 w2 J3 ^
The oscillating member is moved backwards and forwards through an angle of 90° (45° on , y+ S5 z6 l/ s8 i: S" g9 Y4 O, {
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
# w; Z9 E4 b& y; F' C# z; T% ymin. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
* H1 i G1 N0 f' P- O3 ~" ^$ zsample is turned through 90° about the centre line of the cord guard.
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翻译成中文的主要意思就是：7 u6 u" W9 r! T/ g; }1 b8 z4 f4 X* J
/ I- \3 l2 o9 i# zThe oscillating member is moved backwards and forwards through an angle of 90° (45° on
. |9 h' m1 q' }3 w& y- beither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per ( |7 K9 H0 y1 k- x
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。; \; { i9 v7 g. ?0 d# F* L0 o. F9 N
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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。1 n. p4 o! |4 ~9 x' Y
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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°。6 h: k% Q. O( t: R- s( }
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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。- a" D' R! O0 s5 y9 A" X5 m9 C* |% k
; ?& `9 l- [' M1 S3 k1 J, v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。4 N N& z+ X" A0 b5 ?5 z* O
/ D8 \7 O& c( V* b1 L/ q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：) J6 `2 I1 {5 l& a
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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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发表于 2009-5-7 20:39
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