Platinum:
resistivity, rho=1.042 x 10-7 ohm-m
thermal coeffiecient of resistance, TCR = 3.7 x10-3 per degree K
poisson's ratio, nu=0.39
coefficient of thermal expansion, CTE = 9 x10-6 per degree C
Gold:
resistivity, rho=2.24 x 10-8 ohm-m
thermal coeffiecient of resistance, TCR = 3.4 x10-3 per degree K
poisson's ratio, nu=0.42
coefficient of thermal expansion, CTE = 1.42 x10-5 per degree C
Predicted and Actual Values:
|
predicted dimensions(m) |
actual dimensions(m) --average |
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|
platinum |
gold |
platinum |
gold |
|||
|
rho(ohm-m) |
1.04E-07 |
2.24E-08 |
1.04E-07 |
2.24E-08 |
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|
TCR(per degK) |
3.70E-03 |
3.40E-03 |
3.70E-03 |
3.40E-03 |
||
|
Poissons ratio |
0.39 |
0.42 |
0.39 |
0.42 |
||
|
CTE(per deg C) |
9.00E-06 |
1.42E-05 |
9.00E-06 |
1.42E-05 |
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|
width(m)= |
7.50E-05 |
1.50E-04 |
6.00E-05 |
1.28E-04 |
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|
thickness(m)= |
1.00E-07 |
5.00E-07 |
1.00E-07 |
4.50E-07 |
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|
length of turn(m)= |
2.50E-03 |
varies |
2.50E-03 |
varies |
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|
spacing of turns(m)= |
7.50E-05 |
7.50E-05 |
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|
number of turns(m)= |
11 |
11 |
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|
largest |
largest |
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|
total length (L) = |
2.75E-02 |
7.62E-02 |
2.75E-02 |
7.62E-02 |
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|
area (A)= |
7.50E-12 |
7.50E-11 |
6.00E-12 |
5.76E-11 |
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|
Resistance (R) =rho*L/A= |
382.07 |
22.76 |
477.58 |
29.63 |
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|
gage factor=(dR/R)/(dL/L)= |
1.78 |
1.84 |
1.78 |
1.84 |
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|
=1 + 2*nu + (drho/rho)/(dL/L) |
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