Tensile tests for metal specimens such as wires are often performed in small series of 5 to 20 single specimens. This provides a statistical value for the test results and can identify individual deviations. The time required for testing a series with 20 specimens is somewhere between 15 and 45 minutes, depending on specimen strain and testing speed. If multiple operators perform the tests, the results generally show greater variance. Even different hand temperatures can be a contributing factor.

There is great potential for improvement through the automation of these testing processes, and Zwick has developed a small automatic feed system with a magazine for 20 samples especially for implementation in the metal industry. Speci-mens whose dimensions have previously been measured are simply placed in the specimen magazine and then tested automatically. In a statistical sense, the handling system functions as a single operator and places the specimens in the test-ing machine in exactly the same position every time. This solves the problem of different hand temperatures and the reproducibility of test conditions is guaranteed. The testing machine and robotic feeding system are controlled by Zwick’s proprietary software, testXpert® II, and at the end of the test series the results can be printed on a test report, exported to a database or Microsoft Office program, and/or stored in a special data file with all control parameters used for the test.

The major benefit of this system is that it avoids repetitive processes for operators enabling them to be deployed on much more important tasks. Because of improved testing efficiency the system generates tests results faster, with signifi-cantly higher integrity, and is quickly amortized.