Instron AVE2, Operator'S Manual

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2. Select the video extensometer icon under System Settings to open the Transducer
Settings dialog for a video extensometer.
The dialog opens in the AVE2 (or SVE2) screen.
3. Position the crosshead and the video extensometer as required for the specimens
that will be tested.
4. For all lenses except the 6mm lens:
a Install the calibration bar in the upper grip only, making sure that the matrix of
dots faces towards the extensometer.
b If necessary, remove the lower grip to avoid damage to the calibration bar.
c
Move the crosshead so that the image of the calibration bar fills the field of view.
5. If you are using the 6mm lens, you must use two calibration bars to accommodate
the large field of view, as follows:
a Install one calibration bar in the upper grip, making sure that the matrix of dots
faces towards the extensometer.
b Install one calibration bar in the lower grip, making sure that the matrix of dots
faces towards the extensometer.
c Move the crosshead so that the upper bar is near the top of the field of view and
the bottom bar is near the bottom of the field of view. Make sure, however, that
the bottom bar is at least 50mm above the bottom of the field of view to optimize
accuracy.
6. Select Calibration.
The dialog moves to the Calibration screen.
7. Remove the red lens cover (AVE2 only; there is no lens cover on the SVE2) by gently
pulling it away from the lens.
8. Follow the instructions in the calibration dialog to select and focus the lens.
a Select the lens that you have installed from the drop-down list.
b Focus of the lens until the check mark appears, then lock the thumb screw.
9. Replace the red lens cover (AVE2 only).
10. In the image window in the Calibration screen, drag the dotted center line so that it
is in the center of the dot matrix pattern.
11. Draw a box around the area of the dot matrix that you want to calibrate. The border
of the box displays green.
If you are using the 6mm lens, draw the box so that it includes both calibration bars.
12. Select Calibrate.
13. When calibration is complete, the calibration status updates and a yellow box
appears indicating the region in the field of view that generates the highest accuracy.
You should ensure that the dots defining the gauge length on each specimen are
within this yellow box at the start of each test.