PASCO Specialty & Mfg. Materials Testing Machine ME-8236 ユーザーズマニュアル

Materials  Testing  Machine

Appendix B: “Seating” a Test Sample and Setting a Pre-Load

In the following procedure, a test sample is stretched and relaxed to properly “seat” the sample (remove any slack) and a 
pre-load is set. 

1. Mount a test sample onto the Materials Testing Machine. Make sure that the Load Bar Round Nut is slightly loose and not 

applying a force on the test sample. 

2. In the Capstone software, set up a Graph display of Position versus Force, and a Digits display of Force.

3. Click Record.

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NOTE: If the position and force data on the graph are not zero, check the “Properties” window in the “Hardware Setup” 
panel. The check box for “Zero Sensor Measurement at Start” should be checked. 

4. Turn the crank clockwise about a quarter of a turn and note that the position and force data are being plotted on the Graph 

display. 

5. With data still being recorded, slowly turn the crank back counter-clockwise. Watch the Digits display, and turn the crank 

to reduce the force to between 10 and 20 N. Don’t let the force go back to zero. 

6. Turn the crank clockwise to increase the force as before. Notice how the second plot of data looks on the graph compared 

to the first. If the second plot of data “tracks” on top of the first plot, then the sample is properly “seated” and you can 
click Stop. If not, repeat the process of applying force and then unloading the force.

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NOTE: Usually it is necessary to load and unload the system several times to remove all the slack and “seat” the test sam-
ple. 

7. When two consecutive plots of data track on top of each other, the test sample is properly “seated”. Click Stop.

8. Click Record to begin collecting data and increase the force back up to 100 N. Click Stop and DO NOT change the crank 

position. Since the Materials Testing Machine is set to automatically zero itself the next time you start recording data, this 
puts a pre-load of 100 N on the sample, which results in better data.