Chapter12 - Basic Transducers

Exa 12.1 page 244

In [1]:
K=4 
strain=1*10**-6 
R=150 
dR=K*strain*R*10**6 
print "Change in resistance = %.1f micro-ohm"%(dR)

Change in resistance = 600.0 micro-ohm

Exa 12.2 page 244

In [2]:
from math import pi
d=0.03 
a=pi*d**2/4 
f=40000 
l=0.5 
E=3*10**10 
dl=f*l/(E*a) 
print "Change in length = %.6f m"%(dl)

Change in length = 0.000943 m

Exa 12.3 page 245

In [3]:
d=10**-4 
A=6*10**-3 
permitivity_absolute=8.854*10**-12 
permitivity_relative=1
C=permitivity_absolute*permitivity_relative*A*10**12/d 
print "capacitance = %.2f pF"%(C)

capacitance = 531.24 pF

Exa 12.4 page 246

In [4]:
print '1.5 cm core displacement produces 6V so'
d_15=6 
d_18=1.8*d_15/1.5
print "1.8 cm core displacement produces = %.2f V"%(d_18) 
d_08=(-0.8)*(-d_15)/(-1.5) 
print "-0.8 cm core displacement produces = %.2f V"%(d_08) 
d_06=(-0.6)*(-d_15)/(-1.5) 
print "-0.6 cm core displacement produces = %.2f V"%(d_06) 

1.5 cm core displacement produces 6V so
1.8 cm core displacement produces = 7.20 V
-0.8 cm core displacement produces = -3.20 V
-0.6 cm core displacement produces = -2.40 V

Exa 12.5 page 247

In [6]:
k=4*10**3 
dx=0.04 
m=0.1 
acc=k*dx/m 
accg=acc/9.8 
print "acceleration=%.2f g"%(accg)
fn=(1/2*pi)*(k/m)**0.5 
print "Natural Frequency = %.2f Hz"%(fn)

acceleration=163.27 g
Natural Frequency = 0.00 Hz