A Remote Reflecting Fiber Optic Method for Detecting Liquid Occurrences Over a Distance of 3 Kilometres

This article introduces a method for detecting liquids over long distances that is based on measuring the difference in the detected reflected power from the end of a conventional single-mode fiber in different mediums. The power of reflected light is affected by the medium outside the fiber, as well as the maximum distance between the sensor end and the detector. The proposed approach was tested on a length of 3.01 km. An investigation of the greatest distance with commercially available laser diodes (MQW - DFB) and a PIN diode is provided; remote measurements at distances more than 34 km are theoretically possible in ideal conditions. We found that the usage of reflecting connectors is the primary constraint in obtaining theoretically calculated distances.