MTS 85X Damper - Manual (Page 32)

Damper System Operation 32
Install the Specimen
Operation
5. Turn on low hydraulic pressure; turn on high hydraulic pressure if low
pressure is not available.
6. If there is a specimen in the load unit, remove it.
Note The actuator starting position depends on the type of test being set up.
7. Ensure the control panel Set Point control is enabled by the controller
software. Adjust the Set Point control to move the actuator to its start
position (usually mid-displacement).
8. This step pressurizes the lift actuators. The crosshead may have shifted
position while hydraulic pressure was turned off.
Note Cap screws clamp the crosshead to the columns during shipping and
maintenance. They must be loosened before moving the crosshead.
Briefly turn the Lift Control to the lift crosshead position to apply a slight
upward pressure to the crosshead. Then return the lift control to the stop
position.
9. Use the Lock Control to unclamp crosshead. Wait 30 seconds for the
pressure in the crosshead locks to drop to zero.
Do not leave a crosshead unlocked.
It can drift slowly down when hydraulic pressure is turned off and damage
any test fixtures, grips, and specimen in its path.
Unlock the crosshead only to reposition it. Always lock the crosshead after you’ve
repositioned it.
10. Use the Lift Control to move the crosshead to a point where you can install
the specimen (or specimen fixture) into the upper grip or fixture without
obstruction.
11. Use the Lock Control to clamp the crosshead to its current position. The
clamped symbol is shown at the right. Wait 30 seconds for the locks to fully
clamp the columns.
12. Install the specimen into the upper grip or fixture. Depending on your test
requirements, zero the force transducer signal to remove the tare weight
from the signal.
Note Always lower the crosshead to where you want it. The pressure
remaining in the lift cylinders after raising the crosshead can slightly shift
its alignment. Lowering the crosshead to its final position removes this
pressure and improves alignment.
13. Use the Lock Control to unclamp the crosshead. Wait 30 seconds for the
pressure in the crosshead locks to drop to zero.
14. Use the Lift Control to move the crosshead to a position where you can
mount the lower end of the specimen (or specimen fixture) into the lower
grip or fixture.
WARNING