MENENTUKAN KOEFISIEN EKSPANSI LINIER MATERIALKUNINGAN DENGAN TEKNIK ESPI

Abstract

Have performed experiments to determine the coefficient of linear expansion of brass rod with a technique ESPI (Electronic Speckle Pattern Interferometry). Dimensions of the test object that is used has a diameter of 45 mm, length 44 mm, and heated from 30 ° C to 40 ° C using a heater affixed to the back of the object. Speckle image data during heating was observed and every interval of 1 minute is stored in computer memory for further processing. The processing is done by subtracting to two speckle image pixel per pixel, and the results are displayed on the screen in the form of fringe pattern. Obtained from experiments brass linear expansion coefficient α = (1,96 ±0 ,02)10-5/°C with a standard deviation of the average of 1.02%.

Keywords:  ESPI (Electronic Speckle Pattern Interferometry), thermal, heater, image, the linear coefficient of expansion