Abstract: A fiber optic sensor for measuring level of fluid consists of an ordered array of multiple optical fibers. Each fiber contains a single sensitive element located on a specific level within the range of fluid level change that transmits different light signals depending on either the sensitive element is immersed in the fluid or located above the level of liquid. The input of the fiber bundle is illuminated by an encoded light beam. A decoding system provides detection of the light patterns at the output and processes it to display the readings. Number of fibers in the bunch determines the number of sensitive sections positioned at different levels and, correspondingly, the accuracy of level measurement.