Abstract: A passive transducer apparatus and method of use for producing a useful output light signal in response to a sensed condition. The sensed condition varies the light emitted from a first fiber optic light conductor that is apparently captured or detected by a second fiber optic light conductor. The light captured by the second or collector fiber optic member is the useful output signal which may be made proportional to the sensed condition. The apparent change in light capture may be caused by a relative change in geometry of the fiber optic members, by variation in the coupling fluid or by an external optical member.

Abstract: A passive transducer apparatus and method of use for producing a useful output light signal in response to a sensed condition. The sensed condition varies the light emitted from a first fiber optic light conductor that is apparently captured or detected by a second fiber optic light conductor. The light captured by the second or collector fiber optic member is the useful output signal which may be made proportional to the sensed condition. The apparent change in light capture may be caused by a relative change in geometry of the fiber optic members, by variation in the coupling fluid or by an external optical member.