F 427/1 - 2 Automatic Strength Tester for Yarns: XTZ - X-changeable Tensile Testing Concept by Zweigle The automatic thread feed operates with pneumatic control, and can perform up to 200 tests per hour. Just like the testing machine it receives its instructions via the PC. The X-changeable Tensile Testing Concept by Zweigle is a comprehensive testing system in which both the software and hardware components are of modular design, capable of being upgraded at any time. The hardware and software flexibility allows the machine to be custom designed. One machine can performe automatic yarn tests, lea tests, and tests on fabrics. The testing machine is supplied in three models: F 427/1: 24 bobbin automatic feed, pneumatic clamps and bobbin changer F 427/2: 1 bobbin automatic feed with pneumatic clamps