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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 :" |/ Y! r5 d8 }7 W+ _, ~+ h+ z
The oscillating member is moved backwards and forwards through an angle of 90° (45° on ! Q9 q9 S3 k3 ~( U& o4 X5 _
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
& v8 r0 S' W- @$ V3 v" c; q& ~) I2 _min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
# Z* J, E3 l8 O/ Y& Jsample 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。0 a) _; q- C( T8 q8 z
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翻译成中文的主要意思就是: ?" s7 @3 @" [! Z1 L# n+ P
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The oscillating member is moved backwards and forwards through an angle of 90° (45° on
4 F- m: o3 F( u+ R: ieither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per ( I# j4 Y2 f! G$ q' `
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。. r1 Y( P/ X2 Q, \- x$ B
! N3 U( B* q0 t* E! Z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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6 K8 z+ x/ W* ^) d! @2 ]0 b: SAfter 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°。+ I0 L" s) Y5 r* l
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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。2 k4 A: M# Y9 N( A$ Y/ @" p
/ t5 k9 @3 b; V" J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:
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- J: `; B! S! c# e& f& F, m$ |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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