Experimental Procedures

1. Select either a steel or aluminum instrumented bar and place it in the testing machine.

2. Connect the wires from the strain gages to the P3500 strain indicators (using the quarter-bridge configuration).

3. Zero the amp on the strain indicator.

4. Input the gage factor. The GF for the strain gages is printed on the bar.

5. Switch the strain indicator to "Run".

6. Load the specimen slightly to ensure it is adequately gripped in the testing machine.

7. Zero the load dial on the testing machine.

8. Balance the strain readings. You can use any value as a reference value. Remember that lateral strains will be negative.

9. Load it up and record strain readings.  Use ten 500 lb. readings for the aluminum bars.  Use ten 1000 lb. readings for the steel bars.

10. Perform a quick check on the results (they should be linear). If something looks wrong, unload the bar and run the experiment again.