Fiber-Optic Volumetric Sensor Based on Beer-Lambert Principle

We report the working of a simple and inexpensive fiber-optic volumetric sensor. It is based on the famous Beer-Lambert principle where intensity of a collimated light beam while passing through a medium attenuates because of absorption caused by the medium. For a specific liquid medium, the amount of light intensity absorption varies exponentially with the thickness of the medium. Depending on the nature of liquid medium, volume variation as low as 0.3 ml could be detected with our designed senor system when measured in a cylindrical container of diameter 15 mm.