Laser extensometer
A laser extensometer is an optical measuring device for non-contact deformation measurement in materials testing. Characteristic values such as expansion and the exact time of specimen break can thus be determined in the tensile test . The expansion can typically be determined to within a few micrometers.
With drift-free systems it is possible to carry out long-term measurements . Among other things, conclusions can be drawn about permanent deformations under permanent load, which serve to select and improve the material.
Working principle
Markings are applied to a tensile specimen . When applying, care is taken that the markings do not affect the properties of the fabric. A laser scanner scans the sample surface along a line parallel to the direction of the force. The laser beam is diffusely reflected on the markings, which is registered by a photo receiver and converted into electrical signals. These are digitized and the software calculates the distances between the marking strips.
See also
Web links
- Longitudinal-transverse laser extensometer (PDF, 91kB) Description of the functionality including sketch, Martin Luther University Halle-Wittenberg
- Laser extensometer - functional principle Information page of the supplier Fiedler Optoelektronik GmbH