Abstract: An experimental device that can measure and display Young's modulus of metal wire online in real time was designed, based on the principle of tiny resistance measurement and based on the relationship equation between the modulus of elasticity and the amount of tiny change in the resistance of metal wire. When the metal wire is stretched and causes a small change in resistance, the magnitude of Young's modulus can be displayed in real time on the display after being amplified by a two-stage integrated operational amplifier circuit, analog/digital conversion, microcontroller acquisition and calculation. The data measured on a 0.201mm diameter steel wire and a 0.269mm diameter constantan wire show that the Young's modulus of the wire measured by this device has a relative error of no more than 0.3%, high accuracy, simple operation and short measurement time, and provides a feasible method for rapid measurement of the Young's modulus of the wire.

Key words: Young's modulus, micro resistors, metal wire, four-ended lead method