The increasing use of powerful miniaturized mechanical and electromechanical units is influencing product development in many sectors, including the automobile industry and medical technology. Springs used for these applications are also becoming ever smaller, but must still deliver precision and reliability, placing greater demands on testing technology.

To meet this challenge, Zwick has developed a new high-precision spring-testing instrument featuring fast, easy operation. This hand-operated spring tester records spring compression stress-strain characteristics in full, with no need to stop at the measuring points. Load and deflection are recorded synchronously.

Intensive development work has created a concept that guarantees highly accurate test results. One important factor in this is mechanical compensation of load cell deformation, ensuring maximum precision in deflection measurement under load (resolution 0.12µm). The reference line of the deflection measuring system lies along the same axis as the spring length being measured. That practically eliminates the length measurement error.

Other important factors in providing highly accurate measurement are the extremely stiff load frame and load application aligned to the specimen centerline, resulting in minimal elasticity through the entire test arrangement.
Integrated mechanical overload protection of the load cell provides reliable damage prevention, avoiding tester downtime and load cell replacement and calibration costs.
The machine possesses three adjustable mechanical limit switch stops for starting position, pre-stress length and minimum permissible test length.

The new spring tester is suitable for production line use and in design and development, while standard interfaces enable connection of additional measuring equipment such as dimensional measuring devices.

The addition of the proven testXpert® II testing software to the manually-operated spring tester produces an ideal package for testing small springs and ensures simple, quick, safe and reliable testing.

The testXpert II test program is ideally adapted to the requirements of spring testing. Contents include integrated histogram and statistics functions, pre-defined specific results, online graph and test result recording plus optional statistical process control (SPC) functions, while flexible, efficient interfaces allow testXpert II to communicate with an organization’s IT infrastructure.