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引用第10楼franco于2009-05-07 20:39发表的 :4 ?8 @# ^- G( s+ w6 Y& ^
The oscillating member is moved backwards and forwards through an angle of 90° (45° on
0 A0 i: T k+ F) w& Heither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per
8 Y. F6 J' f. d1 d4 [$ K3 t% wmin. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the 3 `/ N# [0 f$ F
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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4 F( c, Q6 w: Q1 j1 G翻译成中文的主要意思就是:, U F4 }$ e; T' G$ m* Z- K6 j3 y- A
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The oscillating member is moved backwards and forwards through an angle of 90° (45° on
" V0 w) W" z; r4 P, jeither side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per 8 s5 U9 a0 m) S7 O8 U
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。
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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。7 v; p& Q3 E0 b& W
0 x( U3 a" |6 s1 Y# p6 y8 ?, `. GAfter 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°。/ P2 g. P# s& j. o, F
$ Q( Q* c3 y* j. 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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* y. a) V2 J5 f; d/ D" ?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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3 X" c) Q4 ]# x+ l; G, W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°。0 H/ S1 [3 K( i4 p& h) x
* b$ @% @5 |. Z4 P- s, C! d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:0 t1 |/ I! K! o8 [/ S0 H) ^, ^
" N+ ~2 d/ q. q0 b+ q7 UA 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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