Patent ID: 7161165

Claim:
An optical transducer for determining liquid level within a container, the optical transducer comprising: a first sensing probe having a first elongate measurement face and a second elongate measurement face that converges toward the first elongate measurement face, at least a portion of the first and second elongate measurement faces being oriented at an angle less than 90 degrees; a first light source positioned for directing radiant energy into the sensing probe; a first photosensor positioned for detecting an amount of radiant energy exiting the sensing probe; wherein a change in the amount of radiant energy as detected by the photosensor is indicative of a change in liquid level within the container; a liquid level switch for sensing a predetermined liquid level within the container, the liquid level switch comprising: a second sensing probe having an elongate core with a measurement tip; and a second photosensor positioned for detecting an amount of radiant energy exiting the second sensing probe; wherein a change in the amount of radiant energy as detected by the second photosensor is indicative of the predetermined liquid level.