Abstract: 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.