Dakota MAX II, Operation Manual

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Dakota Ultrasonics
108
adjusted, approximate length already entered, and the MAX II is currently setup
and ready to measure in elongation mode.
2) Apply a drop of couplant to the bolt or transducer, and attach it to one end of
the bolt. Rotate the transducer clockwise and counter clockwise applying a
small amount of pressure to eliminate any excess couplant between the
transducer and bolt. Be sure to always place the transducer in the same
location . This will help to eliminate any potential measurement errors
caused by changing the sound path.
3) Record the ultrasonic length “L
0
” of the sample bolt at the above minimum
temperature - 48
0
F.
4) Repeat step 1 - 3 at the target temperatures (T
1
through T
5
) – 48, 68, 88,
and 108
0
F (other similar range with 5 temperatures), measuring the
ultrasonic lengths (L
1
through L
5
) respectively. This process must be done
for each of the sample bolts in the experiment.
5) Use the equation below to calculate a linear regression, using the
temperatures and lengths recorded for all the sample bolts to determine the
temperature factor.
  
 
6
2
2
10







 
n
x
x
n
y x
xy
eFactor Temperatur
x = temperature, y = change in reference length, n = number of sample points per bolt