Instron DX Series System Concepts Manual

Chapter 3: Additional System Details
46 M47-17028-EN
8
• During a tensile test, the load
reading stays steady or jerks up or
down (instead of moving at a
consistent rate) while position
increases
• Motion is visible between the
specimen and a crosshead (i.e.
specimen stays still while crosshead
is moving or vice versa)
The specimen is slipping in the
grip jaws, possibly due to:
• Specimen not seated
properly
• Unload the specimen and reclamp
the grip jaws on the specimen
• Incorrect grip jaw type for the
specimen being tested
• Determine the best grip jaw type for
your specimen (refer to information
provided in the System Operating
Instructions (supplied separately))
• Damaged grip jaws • Inspect the grip jaws (refer to
maintenance information provided in
the System Operating Instructions
(supplied separately))
• Improperly lubricated grip
components
• Check lubrication of grip
components (refer to maintenance
information provided in the System
Operating Instructions (supplied
separately))
• Insufficient initial clamping
force
• For frames with G1-style crossheads:
Use additional force to clamp the grip
jaws on the specimen, but DO NOT
hammer grip components.
• For frames with G7-style crossheads:
Watch the pressure gauge on the
grips manifold while clamping the
specimen, it should read
approximately 20.7 bar (300 psi). If
it does not, or if this seems
insufficient for your testing needs,
contact your local Instron Services
department as directed on page 13.
9
• During a tensile test when an
extensometer is being used, no
elongation is measured
The specimen is slipping in the
grip jaws
See Problem No. 8.
The extensometer cable could be
damaged or have loose
connections
Check the extensometer cable for
damage and check that connections are
secure. If damage is found contact your
local Instron Services department as
directed on page 13.
10
• During a tensile test, a clicking
sound comes from the grip jaws
• During a tensile test, a bump
appears in the graph
• Galling or scuffing of the grip jaws or
grip pocket is observed
• Bending, tearing, or scarifying of the
wear plates (see example shown in
Chapter 4 of the System Operating
Instructions (supplied separately).
The grip jaws are improperly
lubricated
Unload the specimen and remove it from
the grips. Relubricate grips as outlined
in the System Operating Instructions
(supplied separately). Assemble grip
components and install specimen in grip
jaws.
Table 5. Troubleshooting the DX system. (Continued)
No. Possible Indications Possible Problem Solution

Instron DX Series Specifications

General

Brand	Instron
Model	DX Series
Category	Test Equipment
Language	English