Checkline TI-MINIMAX - Manual (Page 97)

MINI-MAX Ultrasonic Bolt Tension Monitor
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 cause by changing the sound path.
3) Record the Ultrasonic Length at Zero Load “L
U0
”.
4) Repeat step 2 & 3 for each sample bolt.
5) Place the first sample bolt in the loading apparatus. Apply
approximately 1/3 of the maximum load, which is to be placed on the
bolt under actual working conditions. Using the mechanical measuring
device, measure and record the Mechanical Length at Load 1 “L
M1
” for
the current sample bolt.
6) Apply a drop of couplant to the bolt or transducer, and attach it to one
end of the bolt. Ro tate the transducer clockwise and counter clockwise
applying a small amount of pressure to eliminate any excess couplant
between the transducer and bolt. Measure and record the Ultrasonic
Length at Load 1 “L
U1
”for the current sample bolt.
7) Increase the applied load to approximately 2/3 of the maximum load,
which is to be placed on the bolt under actual working conditions. Using
the mechanical measuring device, measure and record the Mechanical
Length at Load 2 “L
M2
” for the current sample bolt.