Patent ID: 6851314

Claim:
An apparatus for detecting loss of liquid from a body of contained liquid having a surface, said apparatus comprising: a first container having an upper end, a lower end, an inner cavity and at least one opening allowing contained liquid to flow in and out of said inner cavity when said first container is partially submerged in the contained body of liquid with the container upper end extending above the surface of the contained liquid so that a liquid surface forms in the first container level with the surface of the contained liquid; a load cell submersible in the contained liquid and positioned at a lower end of said first container within the inner cavity, for measuring a weight bearing thereon; and a second container having an upper end, a lower end, and an inner cavity closed to liquid flow, said second container positioned within the inner cavity of said first container having its lower end resting upon said load cell so as to bear no detectable weight thereon when the second container's inner cavity is filled with a volume of the contained liquid to a level even with the surface of the contained body of liquid.