Stress Relaxation Tester EB 02
For
Testing of Stress Relaxation
Relaxation system for continuous measurement in either
compression or tension. Meets the requirements in ISO 3384
and ISO 6914.
The relaxation rigs are used in combination with the cell
oven EB 01 or EB 07 when testing at elevated temperatures. |
The room temperature box is used when testing
at room temperature to avoid variation in the load curve caused
by temperature variation in the laboratory. |
The relaxation rigs are placed in a cell oven for
testing at elevated temperatures.
The cell oven EB 01 can accommodate four rigs
at one temperature. In the cell oven EB 07,
three rigs can be placed at three different
temperatures. |
Draught Hood, to eliminate
variations in force measurement
due to temperature
and air effects. |
 |
Relaxation
rigs arranged for different test methods.
Rig 1 is arranged for testing in compression according to
ISO 3384.
Rig 2 is arranged for testing in tension according to ISO
6914 method A.
Rig 3 is arranged for testing in liquid according to ISO
3384.
|
 Graph
1
The graph shows F/F0 curves for SBR tested at different temperatures. |
Graph
2
The blue curves shows the influence of room temperature variations
in the force curve. The red curves shows a rig placed in the
room temperature box. |
Graph
3 |
Graph
4 |
| Graph 3 and 4 shows the repeatability
of the relaxation rigs. Graph 3 is a graph from two tests of
the same compound run at different times. Graph 4 is a graph
from two samples of the same compond run at the same time in
different rigs. |
Graph
5 |
Graph
6 |
| Graph 5 and 6 shows how to
correlate for the spring effect in the load cell and rig, when
doing very accurate tests. The spring effect is caused by the
expansion of the load cell and rig when the force decreases
with time. Graph 5 shows a manual correction done twice during
the test, by manual adjustment of the compression. Graph 6 shows
a correction done by the software by a mathematical calculation.
The correction is not necessary when doing comparative tests. |
Graph 7
Graph
8
Graph 7 and 8 shows how to use relaxation data
to estimate the life time of a rubber compound for sealing
rings, according to the procedure in ISO 11346.
Data from relaxation tests done at three temperatures are
plotted in a graph and the "end of life" is determined for
each temperature. This data is then plotted in an Arrhenius
graph with ln time against 1/T, where T is the temperature
in Kelvin. A linear extrapolation can be done for lower temperatures
to establish the estimated life time of the tested compound.
|
Technical
Specifications of Stress Relaxation Tester |
Temperature Control |
| Range, in compression |
800N or 1800N |
| Tension |
70N |
| Accuracy |
±0.1% of full range |
| Resolution, Compression |
0.1N or 0.2N |
| Tension |
0.01N
|
| Dimensions, dia x h |
120mm x 450mm |
| Weight |
approx 4.5Kg |
| Material |
Stainless steel |
| Temperature Sensor |
PT 100, 1/3 DIN
|
|
|
| The Equipment works with continuous stress relaxation
measurements in both compression and tension. The basic version
can do tests according to ISO 3384 in air. The rig works together
with the cell ovens EB 01, EB 07 and the programmable temperature
cabinet, EB 02.09. |
Options |
| EB 02.01 |
Container and pressure plate (with a hole in the center) for measurement in liquids, according
to ISO 3384. |
| EB 02.01P |
Sealed container for testing of stress relaxation in volatile liquids
and coolants up to 3 Bar pressure. |
 |
| EB 02.02 |
Grips
for testing relaxation in tension, according to ISO 6914.
|
| EB 02.03 |
Load Cell 70 N for tests in tension, including adapters.
|
| EB 02.04 |
Expansion Sleeve for good heat transfer in the cell oven.
|
| EB 02.05-4 |
Amplifier box with inputs for 4 load cells and 4 PT 100 sensors. (4 rigs)
|
| EB 02.05-8 |
Amplifier box with inputs for 8 load cells and 8 PT 100 sensors. (8 rigs)
|
| EB 02.06 |
Multitasking software for PC-computer with data logging and analysis.
Up to 20 EB 02 rigs and 5 EB 025 amplifier boxes can be connected in a network. The results
can be presented as a graph with F/F0 against log time.
Programme versions with up to 128 rigs are available.
|
| EB 02.08 |
Room
Temperature Box, 23 °C, for testing at standard laboratory
temperature. Keeps the temperature constant within ±0,2 °C. The
box can take 4 rigs.
|
| EB 02.09 |
Programmable
temperature cabinet, -50 °C to +180 °C, a modified Thermotron
temperaturecabinet that can accomodate 8 EB 02 relaxation rigs.
|
| EB 02.10 |
Draught
Hood, to eliminate variations in force measurement due to temperature
and air
effects. This hood is made of Plexiglass and has a temperature
controlled system with a
Peltier cooling element, capable of keeping the temperature
within ± 0,2 °C. The hood fits
both EB 01 and EB 07.
|
| EB 02.11 |
Draugh Hood for temperature cabinet EB 02.09
|
| EB 02.12 |
Container for testing in liquids in tension.
|
| EC 05 |
Basic software for stress relaxation testing
|
Rubber Testing Main Page
For
more information or to request a quotation, please E-mail our sales
department at: sales@qualitest-inc.com
, or call us toll-free
at: 1-877-884-TEST.
|
