Liquid level sensor using fiber bundle

Liquid level sensors can be constructed using a pair of bundle probe based on fiber-optic displacement sensor. The working mechanism of the sensor is detecting displacement in the reflector which is attached to membrane (reflector displacement device or RDD) due to changes in the level of the liquid. Displacement of reflector is detected through changes in the intensity of reflected light from reflector into an optical fiber that serves as the recipient of the light. Other optical fiber acts as a transmitter of light. Three types of RDD was used in this experiment, namely RDD consisting of 1, 2, and 3 layers of the membrane. The best performance is shown by the sensor using RDD with 1 layer membrane. Sensor range, linear region, sensitivity, and resolution sensor generated each of 115 cm, 110 cm, 0.37 mV/cm, and 1.45 cm.