Optical contactless measurement technics for industry research and development

ECM Datensysteme GmbH


Extension measuring system DHE

Optical extensometer type DHE 403


The extensometer type DHE 403 is a computer-based automatic optical extensometer for the measurement of the elongation of a specimen during the test by tear test machines. It is designed as an enhancement of machines with existing electronic evaluation.
After the start of the tearing process the devices delivers continuously the elongation of the probe. The measurement accuracy is amount to about 0.001 to 0.002 mm depending on the length of the specimen. After the break of the probe the system delivers the uniform elongation Agt and the elongation at break A10, A5 and A11.2. The measurements are made in accordance to the known European and international standards and comply with manual measurements. For this the uniform elongation will be measured over a distance of 100 mm in an area 5*D beside the break and the elongation at break will be measured centered over the break point.


Tensile strength machine extension type DHM 403


The device type DHM 403 is a system for the modernizing of tensile strength machines. With it you can add electronic data acquisition and processing and the optical extensometer system to older machines.
Additional to the above described extensometer the device DHM 403 includes an universal program for the tensile test at metal and other materials. With this program it is possible to acquire data from tensile tests automatically, to store it, to generate protocols according to all actual standards and to construct statistical evaluations.

The devices will be installed and fixed lateral or behind the tear test machine. They will be calibrated through an automatic calibration function by a certified calibration rod according to this position. Every testing institute can make the recalibration of the device regularly.




DHM main window

Optical distance measurement system type WM 404


The task of the distance measurement system is the contactless optical measurement of change in length during the tensile strength test over arbitrarily definable distances. In opposite to the devices DHE and DHM here you can examine length changes on all sides of the object and it is possible to combine these changes later for the interpretation. A special application is the measurement of slippage at reinforced steel assembly.

The distance measurement system determines the following measurements: