MTS Landmark Tabletop - Manual (Page 58)

Install the Specimen
1. Prepare the components for specimen installation.
a) Ensure that the crosshead is locked.
b) Turn on system electrical power.
c) Apply HPU system high hydraulic pressure. Apply load unit station low hydraulic pressure.
d) If the system has a Series 494 based controller, enable the Gate Interlock.
e) Set the actuator velocity limiting switch to the tortoise (restricted flow).
f) Enable the handset and use the thumb wheel to move the actuator to its start position (usually
mid-displacement). The starting position of the actuator depends on the type of fixtures, grips, and the
test being set up.
Caution:
For load units with hydraulic lifts and locks, the crosshead can slowly drift down the columns
if the locks are turned off and when hydraulic pressure is turned off.
The crosshead can damage any test fixtures, grips, and specimen in its path.
Unlock the crosshead only to reposition it. Always lock the crosshead after you have
repositioned it, and never leave the crosshead unlocked.
2. Set the crosshead position.
The crosshead position depends on the length of the specimen being tested, the starting position of the
actuator, and the size of the fixtures or grips being used.
3. Install the specimen.
Specimen installation varies according to the type of grip being used. For installation instructions, see the
appropriate grip manual. MTS manufactures a variety of grips:
• The Series 641 Hydraulic Wedge Grips (hydraulically controlled) are specifically designed for static or
fatigue testing applications. They are available with a self-aligning feature.
• The Series 643.6X Tension/Compression Grips (mechanical) are used for testing threaded-end and
button-end specimens in tension, compression, or tension/compression.
• The Series 646 Hydraulic Collet Grips (hydraulically controlled) are designed to perform in a wide
variety of testing applications (for example, high and low cycle fatigue, tension, and compression).
• The Series 647 Hydraulic Wedge Grips (hydraulically controlled) are specifically designed for static or
fatigue testing applications. There are a variety of configurations of this grip.
• The Advantage Grips (mechanical) are specifically designed for static or fatigue testing applications.
The Advantage Mechanical Wedge grip is the mechanical version of the Series 647 Hydraulic Wedge
Grips. Advantage Grips also come in Screw Action and Pneumatic versions.
58 MTS Landmark™ Tabletop Load Units Product Information
Operation