a tank or vessel volume measurement apparatus that includes multiple buoyancy elements . the buoyancy elements can be placed within a perforated tube to reduce any effects from turbulent flow within the tank . the multiple buoyancy load sensors are each made of different density or cross sections to cancel out any accumulation of contamination that may collect on the buoyancy elements placed within the fluid and to determine the density or specific gravity of the fluid within the tank . the buoyancy elements are attached to a load sensor or strain gauge that measures the weight or load from the buoyancy element . temperature of other sensors can be placed on the buoyancy elements or within the tank to collect other readings or to adjust for temperature variations . the buoyancy elements can be fabricated in pieces and assembled on site or within the tank to accommodate taller tanks or height restrictions .