Fiber optic liquid sensing system

摘要

An optical liquid sensing system for sensing liquids in contact with an optical sensing component is provided. The sensing system comprises an optical sensor connected to a control module by a fiber optic cable having two fiber optic strands, the first for receiving light emitted by the control module, and the second for receiving light reflected from a distal reflector. The strands terminate in a longitudinally oriented common ferrule within the optical sensor. The optical sensor is generally cylindrical and includes a distal reflector opposite and in a spaced relationship to the ferrule. A group of apertures is defined in the circumferential wall of the housing so as to permit entry of liquid into the housing and to draw liquid proximally located to the sensor into the housing via capillary action. When an amount of liquid insufficient to flood the sensor enters the housing, the shape of the sensor and the arrangement of interior components of the sensor cause the liquid to be formed into a liquid cylinder spanningly disposed between the ferrule and the reflector. The reflective inner surface of the liquid cylinder causes the amplitude of a light signal introduced into the housing by the first strand to be increased in amplitude before being received by the second strand. When the sensor is flooded with liquid, the light signal from the first strand is attenuated before being received by the second strand. The control module detects variances in the amplitude of light received by the second strand when the sensor is in contact with or is flooded by a liquid and indicates to a user that presence of a liquid has been detected by the sensor.