MTS Series 646 Hydraulic Collet Grips - Manual (Page 59)

Series 646 Hydraulic Collet Grips Operation 59
Installing a Round or Flat Specimen
To install a round or flat specimen into the appropriate collet assembly:
Prerequisite
This procedure assumes that the proper collet has been selected and is installed.
Procedure
1. Adjust the hydraulic grip supply pressure to the minimum level.
2. Select system force control in the most sensitive range available.
If you use displacement control during specimen installation, you can cause
specimen damaging forces.
Be very careful when manually adjusting the actuator in displacement control
because the actuator will move to reach any command regardless of anything
being in its path.
If only displacement control is available, use extreme care not to apply
specimen-damaging forces in the following steps.
3. Release the upper and lower grips.
4. Place the specimen in the upper grip. Note the minimum specimen insertion
specification in the following table.
5. Lock the upper grip.
6. Apply system hydraulic pressure to the load unit.
7. Extend the actuator until the specimen is properly positioned in the lower
grip. Note the minimum specimen insertion specification in the preceding
table.
8. Lock the lower grip.
M ODEL M INIMUM S PECIMEN I NSERTION
646.10 25.4 mm (1 in)
646.25 50 mm (2 in)
CAUTION