The purpose of this work was to project, build and certify an equipment known as a Proof Ring, that is utilized to test materials under environmentally assisted cracking, since in this situation the material can suffer cracking and may cause abrupt ruptures. Those material tests are extremely useful to analyze cracking behavior, enabling to predict futures structural collapses and effectively improving the machine or equipment projects that utilize such materials under a corrosive environment. The Proof Ring project utilized the software SolidWorks utilizing the specifications proposed by the teacher and later manufactured with the available resources at the workshop, which end up affecting the project itself. Later the ring was instrumented with strain gages connected to a reader via a full Wheatstone bridge. Finally, the equipment was calibrated in a compression machine. Additionally, a physical analysis of the mathematical relation between the ring deformation and the applied force was performed. Such analysis was important to decide were the sensors should be connected aiming to obtain the maximum output signal on the instrument. The relationship between the signal and the deformation was also analytically calculated, therefore been possible to determinate the force applied using the instrument signal output. Overall such work is a mechanical engineering experiment applied to real conditions, in which I applied a multitude of knowledge in the field.