Method and apparatus for storage tank leak detection

Apparatus for detecting leaks in a liquid storage tank comprising: differential pressure sensor means with a component of low pressure measurement component and a high pressure measurement; protective cover means for protecting said differential pressure sensor means from materials and conditions when immersed in liquid contents of said storage tank; It said measurement component configured to measure high pressure pressure tank bottom within a liquid in which said cover means being immersed; It said measurement component configured to receive low pressure data indicative of atmospheric pressure substantially at the surface of said liquid being; measuring means configured to measure barometric pressure atmospheric pressure substantially at the surface of said liquid when said protective cover means is immersed therein; barometric pressure and calculating means differential pressure are configured to receive first and second data reflecting, respectively, said pressure tank bottom and said barometric pressure substantially at said surface of said liquid, and for adjusting said first data to substantially eliminate the variations on those measures that pressure tank bottom only caused by atmospheric pressure variations to yield an atmospheric pressure adjusted to the pressure of the tank bottom; measuring means for measuring ambient temperature near ambient emperature said storage tank; barometric pressure and dynamic adjusted tank calculation means pressure tank bottom configured to receive indicative third data of said atmospheric pressure adjusted to the pressure of the tank bottom, for receiving fourth data indicative of measurements of the ambient temperature by said means for measuring ambient temperature, 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 to the tank bottom pressure, caused solely by dimensional changes in said storage tank resulting from atmospheric temperature variations, to produce a bottom pressure adjusted tank to dynamic tank; means for calculating mass contents of the tank to calculate the mass content of said storage tank substantially based on said bottom pressure dynamic adjusted tank and data user input reflecting the physical characteristics of said content in said storage tank.