MTS Axial Extensometers - Manual (Page 34)

Configuration 34
3. While securely holding the extensometer arm or attachment
adapter, loosen the socket head cap screws with a hex wrench just
enough to remove the knife edges.
4. Repeat Step 2 and Step 3 to loosen the socket head cap screws in
the lower arm.
5. Slide out the existing knife edge.
Note When using heavy duty or extended length knife edges, the
contact edges are off center to maintain the proper gage length.
The orientation of the knife edges will vary depending on the
extensometer model being used. See the knife edge installation
drawing that accompanied the knife edge kit for the proper
orientation.
.
6. Slide the knife edge between the extensometer arm and the knife
edge hold-down or attachment adapter
• Use straight knife edges for round specimens.
• Use three-point knife edges for flat specimens. Ensure that the
single-point contact knife edge is in the upper arm and the
two-point contact knife edge is in the lower arm.
7. Tighten the socket head cap screws only enough to secure the knife
edges.
If straight knife edges are being used, place the flat surface of a
machinist’s square or similar object across the face of both knife
edges to ensure that both edges are parallel to each other.
Heavy Duty Standard
Hold Down
Knife Edge
Cap Screw
Upper Arm