Checkline TI-MINIMAX - Manual (Page 100)

Dakota Ultrasonics
94
Determination of the Temperature Factor is accomplish by solving the equation:
Where:
6
0
0 10
) (
) (
×
−
−
=
T T L
L L
T
T
T
p
Temperature Factor
L
0
= Ultrasonic Length at Beginning Temperature (T
0
)
L
T
= Ultrasonic Length at Ending Temperature (T)
T
0
= Beginning Temperature
T = Ending Temperature
Calibrating the Temperature Factor
1) Stabilize the sample bolt at approximately 48
0
F. If the water bath
method is used this is accomplished in a stirred bath of ice and water.
Measure and record this minimum temperature as T
0.
Note: The following steps assume that the user has performed the steps in
the previous section and calibrated the velocity. Therefore, the velocity has
been adjusted, approximate length already entered, and the MINI-MAX 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.