|
引用第10楼franco于2009-05-07 20:39发表的 :
! c2 E- Q$ J5 i/ ~; t yThe oscillating member is moved backwards and forwards through an angle of 90° (45° on : K" p/ S. C, Q/ G
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per 9 l" g5 h) S) H, N5 T
min. A flexing is one movement, either backwards or forwards. After 10 000 flexings, the
( ^( x- n3 \ M3 Y9 }# l: a( e! Xsample is turned through 90° about the centre line of the cord guard. 8 W- `+ Z$ x5 n0 c7 ]/ J9 a. ~
# R0 F% K/ l0 ?1 {
....... 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 X( u; t( U9 H& a
& ]0 ?! t! m- N翻译成中文的主要意思就是:, t& u _0 x& N
: G8 b" O) \1 L0 h$ RThe oscillating member is moved backwards and forwards through an angle of 90° (45° on # q! M% n- p+ ~& O
either side of the vertical), the number of flexings being 20 000 and the rate of flexing 60 per ; y( o) G0 S1 E$ u, L" u i
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。
/ `+ Y& n! |0 e& L! Z7 n* J/ I* A! X8 Y: @+ {2 v& o6 F/ ~
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。
% ~; j$ X X2 L( p
% |6 {" N7 g; i6 n+ ^6 `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°。" ~( N4 ~" J; p. m! c
3 q+ H, E5 S7 l, p; _0 L
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。
. f9 e2 F2 Y9 j5 M. j0 W9 @0 @4 c& Y5 N
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。
8 u9 {; V: O5 G# w9 V
% x! t/ }' m, ]$ F0 h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°。( O7 Y' l4 w1 K! \. Z
: P" f) T) v, J2 a; B4 E
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:
; x9 `; {4 A$ c5 w! J5 J! Z8 A, M- {( i8 x$ H T& p% A
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. |
|