Optical Path Shifting Interferometry for Determining Water Evaporation

The interferometric method measures water evaporation was conducted by opti-cal path shifting interferometry due to the change in the length of optical path. The height of water that dried up from the glass is equally valuable to the increased length of the light. Counting the number of sinusoidal fringes allowed us to calculate amount of water evapo-ration. The vibration strongly effected to obtained signal. To get better signal from this issue, inserting of cylindrical Al tube successfully reduce the ripple on the top surface of the water. Water evaporation was victoriously measured with warm and cold water even under windy condition (electrical fan).