Apparatus for determining the properties of metallic materials

Claim 1

Apparatus for determining the modulus of elasticity of a metallic material, which comprises: a machine for subjecting a testpiece of metallic material to a tensile test, said machine including mobile member means engaging one of the ends of said testpiece for exerting traction thereon; means applied to said mobile member means for subjecting same to controlled displacements whereby traction is exerted on said test-piece in controlled steps; means for measuring the force applied to said test-piece by said mobile member means as a function of time and for providing data indicative thereof; means for measuring the length of said test-piece as a function of time and for providing data indicative thereof; and a computer which is connected to said mobile member controlled displacement subjecting means, said force measuring means and said length measuring means, said computer including means for processing said data from said force and length measuring means in accordance with preprogrammed formulas stored therein to provide an output indicative of the modulus of elasticity of said metallic material, said computer further including means for providing control signals for controlling the movement of said mobile member controlled displacement subjecting means; said length measuring means comprising a length sensor which measures the length of said test-piece and an amplifier connected to receive the output of said length sensor; said force measuring means comprising a load sensor which measures the load applied to said test-piece and a variable gain amplifier connected to receive the output from said load sensor; and wherein said apparatus further comprises: a first matching circuit connected to receive the outputs from said amplifier and said variable gain amplifier; an analog-to-digital converter connected to receive the output from said first matching circuit and to deliver an input to said computer; a deviation calibration and correction device connected to said machine, a speed selector connected to said machine, an indicating member connected to said machine for providing an output indicative of the stop position and direction of movement of said test-piece, and a second matching circuit whose inputs comprise the outputs from said correction device, said speed selector, and said indicating member, and whose output is connected to said computer.