The first experimental measurement was meant to set the
ideal size of sensory ring for optical meander in point
mode. It was used multimode optical fiber with tight
outer jacket (external diameter of 900 µm). The sensory
rings with inner diameter in the range from 1,5 cm to
6 cm were created, each ring contained 5 m of optical
fiber. The results of experimental measurement in a water
bath are shown on Fig. 8.