Introducing the eX5M Education Hand Operated Mechanical Force / Stress Tester

AZoM talks to Rich Gedney, CEO and Founder of ADMET to discuss the eX5M Education Hand Operated Mechanical Force / Stress tester from ADMET.

ADMET has been working with educational institutions for many years, could you tell us a little about ADMET systems and why your systems are particularly popular in Education?

ADMET began by upgrading and retrofitting other companies’ machines and thus learned a great deal about these other machines, both pluses and minuses. Key among these characteristics was ease of use, most systems provided by other makers are deemed more difficult or complicated while ADMET is consistently ranked easiest to use. Of course in an academic setting, where only limited time is available for the staff and students to implement a system, ease of use is critical to success.

As an introduction to the eX5M, could you give us a little background on universal testing machines, for example what are they typically used for?

Universal testing machines are frequently used to determine the Ultimate Tensile Strength (UTS), Modulus of Elasticity, Yield and Elongation of specimens made from a wide variety of metals, plastics, textiles, composites or biomaterials. Tests are conducted by pulling (tensile), pushing (compression), peeling, bending and shearing. Some characteristics of the material are more complex such as toughness, stiffness and residual strength, each requires that force be applied at a specified rate while force, extension and time are recorded.

Why would one choose a hand-operated system over an automatic test system?

Cost is the primary consideration for choosing a manually operated machine. Automatic machines are needed for higher force tests, long duration tests or tests requiring precise control of stress or strain rates. In our first 25 years in business, ADMET manufactured only automatically controlled machines.  Manually operated machines are new to our product portfolio.  We have developed a unique approach to allowing manually operated machines to conduct tests in accordance with recognized international standards such ISO and ASTM.

What features of the eX5M have been specifically designed with Educational applications in mind?

The ability to apply forces up to 5kN in tension or compression with very little mechanical effort by the student or staff and doing this in a small portable package. The student receives both visual and tactile feedback thus re-enforcing the behavior of materials. The ability for students to examine and compare results and experiment with the effects of varying mechanical arrangements and speeds leads to a wider educational experience.

Image Credit: Admet Inc.

What are the main benefits of using the eX5M in education?

The eX5M is very economical.  In addition, the indicating system and Windows software provides visual feedback to the student to ensure that the test is conducted at the desired loading rate or test speed. Compared to other manual testing machines, the visual rate indication reduces test speed variability providing more consistent measurements between tests.  Small material differences between specimens has historically been lost due to less sophisticated manual machines as well as many open loop automatic machines which suffer from testing speed variation; the eX5M system makes it possible to discern these differences that lesser system are not able to record. The additional benefit of being able to quickly generate a plot of the recorded data serves as a conduit for more in-depth conversations inside the classroom; thus providing a more comprehensive educational experience.

Offering some pretty impressive capabilities, can you briefly discuss each of the tests the eX5M can perform?

The eX5M can perform a variety of tests including tensile pull to break, compression, bend, adhesive peel, shear, pull out and more.  With these capabilities the user is able to determine a wide range of mechanical properties such as strength, stiffness, toughness, adhesive strength, resistance to sliding, strain rate sensitivity, ductility and more.  In the last decade we have seen a marked increase in the number of new materials introduced into the marketplace.  We expect that trend to accelerate, making it an exciting time to be involved in new material development.  ADMET’s goal with the eX5M is to provide an economical way for budding materials scientists and engineers to learn about the mechanical properties of materials, thus making it more accessible to a wider group of students.

How does the eX5M integrate with other existing systems in the lab?

The software that accompanies the eX5M includes the ability to export the results to spreadsheets and other programs as comma separated data thus allowing a comprehensive test report to be assembled including data from other mechanical testing devices and analytical instruments.

The eX5M features ADMET’s Intelligent Universal Test Indicator (UTI); can you tell us a little more about what this offers the user both during and after a test sequence?

Pulling a specimen until it breaks seems simple enough but if five students were to perform the test on identical specimens it is very likely that the results would vary between tests.  Each student would apply the force to the specimen at a different rate due to their strength, height and dexterity when using other machines. The UTI provides real time feedback to the student, testing speed corrections can be made by simply rotating the load assembly a little faster or slower as indicated on the bar graph display of the UTI. The visual and tactile feedback as to how the specimen is behaving as the force is varied thus helps to reinforce the educators class room instruction.

During the test, the force (kN), position (mm) and time are simultaneously collected to eliminate skew while providing excellent accuracy and sensitivity as specified by ISO and ASTM.  At the conclusion of a test the results of user activated calculations are displayed on the UTI and the test graph is saved to memory. The software operating on the computer captures the test curve and the results of the calculation in real time.  Post test, the curve can be saved, printed or exported into a spreadsheet for further analysis by the student.

The UTI can also be combined with a number of self-identifying plug-n-play load cells, can you tell us more about these options?

Load cells are the transducers that measure the force applied to the specimen and are available in many force capacity ranges. A load cell rated for 5kN is usually operated over 1% to 100% of capacity; 50 to 5000 Newtons.  If forces less than 50 Newtons are required, then a lower capacity load cell would be needed. A rangeability of 10:1 is commonly available in most manual testing systems.  The eX5M expands this range to 100:1 thus the 5kN load cell can be used to forces as low as 50 Newtons.  Depending on your testing needs, an additional lower force load cell may be required.  But how do you make sure that the appropriate low cell has been attached?  The eX5M/UTI system supports intelligent load cell self identification which signals the UTI of it's force capacity and calibration thereby making it possible to know which load cell is in use before beginning a test and also alerting the student prior to the maximum capacity being exceeded thus protecting the load cell from damage.

Image Credit: Admet Inc.

Can you tell us more about the options available for the eX5M?

Testing can be conducted in tension, compression and bend configurations and ADMET offers grips and fixtures, higher resolution position measurement and a wide range of load cells of varying force capacities. Included as standard are software calculation suites that allow a wide range of preprogrammed calculations to be applied to any test. As users identify additional useful calculations, these will be added, so as to expand functionality and support ADMET's ease of use philosophy.