Abstract: A leak detector including a float having a number of magnets connected to the float. Electromagnetic coils are disposed along a length of the possible range of travel of the float within the leak detector. The coils, when energized, interact with the magnet making the float move-about and settle to a position representing its true equilibrium buoyancy. Optionally, the leak detector includes a self-calibration apparatus that provides a reference signal indicting the fixed position of the self-calibration apparatus, allowing the leak detector to compensate for offset errors.

Abstract: An improved leak detection float system for use in underground storage tank containing fuel wherein the float system utilizes an elongated hollow test probe extending downwardly into an underground storage tank and into the fuel stored therein. A microprocessor is contained in an upper compartment of the test probe along with control electronics. A rod is centrally affixed in the lower portion of the test probe and a float is disposed around the rod, but within the test probe so as to float on the surface of the fuel. The float uses tapered edges to minimize offset error due to surface tension. An excitation transducer is placed above the float on the rod which produces vibrational waves down the rod having a predetermined frequency, power, and duration. The vibrational wave breaks the surface tension existing between the float and the fuel so that the float can obtain a position within the fluid based upon the buoyancy of the float in the fluid.

Abstract: Apparatus for detecting leaks in fuel storage tanks. A float suspended in the tank liquid determines liquid levels and transmits the liquid level information via an infrared beam to a probe processor in the upper portion of the tank. The probe processor stores a plurality of level indications for subsequent uploading to an external computer which analyzes the level information to generate leakage rate information.