Abstract
A novel optical viscosity sensor using forward light scattering is presented. The sensor concept is based on the fact that the frequency response of a fiber partially submerged in a fluid is sensitive to the viscosity of the fluid. The viscosity is determined by measuring the vibration of a sinusoidally excited optical fiber. The sensor exhibits an excellent sensitivity for measuring the viscosity. A significant change (≈1-10 dB) in the amplitude of the vibration and a frequency shift of 26 Hz in the response spectrum of the fiber during measurement in air, water and 5-40% sucrose solutions have been observed.