Method and apparatus for storage tank leak detection having temperature compensation.

摘要

A method and apparatus for substantially eliminating measuring inaccuracies in a storage tank leak detection system (22) caused by temperature-induced volumetric changes in the stored fluid product (18) is described. In a preferred embodiment of the method, a limp bladder (34) is connected to an end of a pressure tube (24) having an inlet (30) and a substantially hollow core (32). The pressure tube (24) and the bladder (34) are filled with a medium (42) having a temperature coefficient substantially lower than the temperature coefficient of the fluid product. The pressure tube (24) and the bladder (34) are then supported in a substantially vertical manner in the storage tank (10) such that a first portion of the medium is supported in the bladder (34) in static equilibrium with respect to a second portion of the medium supported in the pressure tube (24). The large disparity between the temperature coefficients of the medium (42) and the fluid product (18) insures that temperature-induced volumetric changes in the fluid product do not vary the level of the medium in the pressure tube (24). Accordingly, variations in the medium level in the tube represent a true indication of leakage of the fluid product out of the storage tank or leakage of a foreign product into the storage tank (10).