Dakota MAX II, Operation Manual

Page: 115 / 216

MAX II Bolt Tension Monitor
107

A minimum of three sample bolts, which are representative of the bolt
type and geometry for which the Temperature Factor is to be determined.
NOTES:

The Dakota Ultrasonics MAX II must be calibrated, or zeroed, as described in the
procedure entitled Measuring System Zero in Error! Reference source not
found. .

The sample bolts should be left to soak at the measured temperature points for a

The sample bolts should be left to soak at the measured temperature points for a
period of not less than 20 minutes, to insure that temperature is uniform
throughout the sample.

If a water bath is used, care must be taken to avoid immersion of the ultrasonic
transducer.
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