Monitoring some liquid cladding layer properties using LED beam transmittance coefficients through the fiber itself

We report work on the adaptation of a conventional optical fiber assembly to monitor the properties of liquid. An LED1 was used in conjunction with a home-made fiber cell fitted with glass fiber rods to monitor some of the physical properties of liquid samples. The technique discriminates between different liquids using their light transmittance ability as cladding layer to the glass fiber. Discrimination between liquids according to their transmission coefficients is partly dependant on refractive index of liquids; therefore, samples were also tested with a refractometer for comparison. Results show that the technique is superior to the refractometer in distinguishing between liquids of different indexes.