Non contact measurement - the video extensometer

The aim of every test is to obtain authentic characteristic values and test results that are not influenced by the testing technique. At the same time, high repeatability is required for the testing technique used.

The video extensometer from FORM+TEST fulfills both requirements at the same time. Non-contact measurement of specimen or component deformation under load ensures that the measurement result is not influenced by contact with the extensometer.

If a structure is already visible on the surface, no additional marking needs to be applied, which makes the application simple. The application software of the extensometer evaluates the recorded images and transfers the data to the controller converted into deformation or according to strain - either as an analog or digital signal. Especially the analog signal is suitable also for an extension of an existing older test system. Despite the high image recording rates of up to 2000 Hz, the software for image evaluation does not require a high-performance computer. In the DIGIMAXX controllers from FORM+TEST this signal is optimally converted for control. The following flow curve of a tensile test according to DIN EN ISO 6892 is shown as an example - stable measured values with high accuracy for reproducible results.

But don't worry, setting up the FORM+TEST video extensometer is very simple, which helps to avoid errors in the application. In the software package "a", the extensometer can be calibrated automatically. In addition, test templates can be created and thus the presettings for different tests and evaluations can be stored. Thus, the extensometer is universally and quickly ready for use and can replace several special extensometers. An additional special feature is the possibility to measure torsional load with only one single camera.

In addition to the classic longitudinal, transverse and bending strain evaluation, a complete area range can also be evaluated with a special software package. This is particularly interesting for inhomogeneous materials, since the weakest area and thus the onset of failure can also lie within the measuring range.

As further extensions, the FORM+TEST extensometers can be used for cyclic tests up to approx. 25 Hz and high-temperature tests up to 1700°C.

For further information please refer to our information brochure VE100.01

Options

• Frame recording frequencies up to 2000 Hz
  
• with different software packages
• Single or multi camera setup
• Version for cyclic tests up to 25 Hz as well as high temperature tests up to 1700°C
• Customized software packages for different use cases