MEASUREMENT OF YOUNG'S MODULUS OF METAL WIRE BY VOLTAGE MEASUREMENT METHOD BASED ON POTENTIOMETER

Using a direct current signal generator, the small changes in the length of a metal wire when it is subjected to force are converted into changes in voltage. Based on the principle of the potentiometer voltage measurement method, the experimental setup used to measure the Young's modulus of the wire has been modified. The length of the resistance wire of the potentiometer was increased from 11m to more than 37m by the method of expanding the resistance, which increased the sensitivity of the instrument by more than 4 times. In addition, a vernier caliper was used to replace the scale of the potentiometer to increase the resolution of the instrument. The modified potentiometer was used to measure the Young's modulus of the conchoidal copper wire, and the experimental data of the measured Young's modulus were processed by the least squares method and the difference-by-difference method. The uncertainty of the measurement was calculated, and the results were compared with those obtained by the tensile method. The measurement results are reliable and can be used for the design, research, and teaching promotion of experimental devices.