Rockwell Testing Aids offers an Electronic Extensometer. This device is used for the determination of proof stress and Young’s module values. With the extensometer it is possible to measure correct strain values within the gauge length marks during a tensile test. In case of ductile materials the stress strain curve is well defined and it clearly shows the yield point, i.e., departure from the straight portion of the curve. But in certain materials like high carbon steels, aluminium and magnesium alloys, the straight portion gradually follows a curve entering into plastic region, making it difficult to determine the yield point, for such cases, it is advised to find proof stress value. The proof stress is a stress corresponding to certain amount of plastic deformation after the proportional limit is passed. In specifications of materials, this plastic deformation is expressed as a certain percentage of the gauge length. Model FEE-5 is especially suitable for determination of Young’s modulus and 0.1 % to 1.0 % proof stress values. FEE-5 is suitable for almost all types of materials. The measurement accuracy satisfied all requirements of IS: 12872-1990/ISO: 9513 – 1989 and ASTM-E-83 class B2. Its reliable construction guarantees maximum safety of operation and longer working service/life also in case of raised application conditions.