Методика измерения перемещений при помощи лазерных интерферометров (WinWord&CorelDraw&MathCad)
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2
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2.1
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3
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3.2
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3.4
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1.
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I=I0+I~* COS (4pL/l), (1)
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I1(t)=I10+I1~*COS[f(t)] ,
(3)
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f(t)=2p*t*fb
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I0(t)=A0 *COS[2p(n1- n2)t+(f1-f2)] ,
(5)
I1(t)=A1 *COS[2p(n1- n2)t+(f1-f2)+ f(t)] ,
A0 A1 - .
N0 N1 -
DN=N1-N0 (. 3).
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f0=f1= u1 -u2, DN=0. 4
f1= u1- u2+Du,
Du=Df(t) / Dt. 2DL= DN*l=(N1-N0)*l.
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Df/2p Dl/l Dn/n
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10-4 10-8 10-9 10-6 10-7
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t , e p.
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(nc-1) - t=15` p=760 . .
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(720 - 790 . . .)
(10 - 30 ..)
( 10 . . .)
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l=0.6329 )
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... n t=100 n t=200 n
t=300
720 1.000266 1.000257 1.000248
730 1.000270 1.000260 1.000252
750 1.000277 1.000268 1.000259
770 1.000285 1.000275 1.000266
790 1.000292 1.000282 1.000273
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t=100
P=790 ... nMAX=1.000292
t=300
P=720 ... nMIN=1.000248
:
Dn=(nMAX-nMIN)/2 Dn/n= 2.200*10-5
:
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Dp=0.1 . . . ( )
Dt=0.1 . . . ( )
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(9)
MathCad 7.0
. (1).
:
Dn/n t=10 Dn/n t=20 Dn/n t=30
P=720 1.314*10-7 1.238*10-7 1.169*10-7
P=730 1.327*10-7 1.250*10-7 1.180*10-7
P=740 1.340*10-7 1.262*10-7 1.192*10-7
P=750 1.353*10-7 1.275*10-7 1.203*10-7
P=760 1.366*10-7 1.287*10-7 1.214*10-7
P=770 1.379*10-7 1.299*10-7 1.226*10-7
P=780 1.393*10-7 1.311*10-7 1.237*10-7
P=790 1.406*10-7 1.323*10-7 1.249*10-7
,
100 790 . . .
Dn/n= 1.406*10-7
3.3 .
:
.
, .
Dl/l=10-5 , Dl/l=10-7 , Dl/l=10-9
:
Dn/n= 1.406*10-7 , Dn/n= 2.200*10-5
Df , :
Df=p/2 , Df=p/16
: L=(1 1 )
MathCad 7.0 (8)
. (2)
:
Dl/l=10-5
.
: Dl/l=10-5 , Dn/n= 2.2*10-5
: Dl/l=10-5 , Dn/n= 1.406*10-7
2. Dl/l=10-7
.
: Dl/l=10-7 , Dn/n= 1.406*10-7
3. Dl/l=10-9
,
Dl/l=10-7 .
: Dl/l=10-9 , Dn/n= 1.406*10-7
3.4 .
:
,
:
:
,
=10,
:
=0.1 .
MathCad 7.0 3 :
Dl/l=10-9 Dl/l=10-7 Dl/l=10-5
p/2 >791 >7.91 >0.079
p/16 >98.87 >0.98 >9.88*10-3
p/2 <7.91 <0.079 <7.91*10-4
p/16 <0.98 <9.88*10-3 <9.88*10-5
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2. .. ..
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