Patent ID: 6854320

Claim:
An apparatus for detecting leaks in a liquid storage tank comprising: differential pressure sensor means having a low pressure measurement component and a high pressure measurement component; protective enclosure means for protecting said differential pressure sensor means from materials and conditions when immersed in liquid contents of said storage tank; said high pressure measurement component being configured for measuring tank bottom pressure within a liquid in which said protective enclosure means is immersed; said low pressure measurement component being configured for receiving data indicative of atmospheric pressure substantially at the surface of said liquid; barometric pressure measuring means configured for measuring atmospheric pressure substantially at the surface of said liquid when said protective enclosure means is immersed therein; barometric pressure and differential pressure calculation means configured for receiving first and second data reflecting, respectively, said tank bottom pressure and of said barometric pressure substantially at said surface of said liquid, and for adjusting said first data to substantially eliminate variations upon said measurements of said tank bottom pressure caused solely from atmospheric pressure variations to yield an atmospheric pressure adjusted tank bottom pressure; ambient temperature measurement means for measuring ambient temperature near said storage tank; tank dynamic and barometric pressure adjusted tank bottom pressure calculation means configured for receiving third data indicative of said atmospheric pressure adjusted tank bottom pressure, for receiving fourth data indicative of ambient temperature measurements by said ambient temperature measurement means, for receiving fifth data indicative of expansion characteristics of said storage tank, and for adjusting said third data with reference to said fourth and fifth data to substantially eliminate variations upon measurements and calculations of said barometric pressure adjusted tank bottom pressure, caused solely by dimensional changes in said storage tank resulting from atmospheric temperature variations, to yield a tank dynamic adjusted tank bottom pressure; and tank content mass calculation means for calculating mass contents of said storage tank substantially based on said tank dynamic adjusted tank bottom pressure and user input data reflecting physical characteristics of said contents of said storage tank.