System for monitoring storage tanks

A monitoring system for a storage tank containing a fluid, said system comprising:

• (a) a body positioned within said tank and extending into the fluid contained by said tank;
• (b) sensor means for sensing the force exerted by said fluid upon said body and providing a first signal representative of said force;
• (c) means mounted within said tank adjacent to said sensor means for receiving said first signal and providing a second signal, said second signal being digitally encoded, whereby said means is maintained at substantially the same temperature as said sensor means and the fluid in said tank, thereby eliminating measurement errors, for example the Seebeck Effect, which occur due to differences in temperature between said sensor means, the fluid in said tank, and said means mounted within said tank;
• and
• (d) first storage means for storing a plurality of first values in a look-up table, each of said first values corresponding to a periodic entry of the force exerted by said fluid upon said body during initial filling of said tank, said first values defining a relationship between the force exerted upon said body at a given fluid depth in said tank and the corresponding fluid mass within said tank, said first values being based on the unique characteristics of said tank, said characteristics including tank shape, volume, orientation, location of said sensor means, and the shape of said body.

A method for sensing the fluid mass in a storage tank containing a fluid, said method including the steps of:

• (a) extending a body into the fluid contained by said tank;
• (b) sensing the force exerted by said fluid upon said body and providing a first signal representative of said force;
• and
• (c) receiving said first signal and providing a second signal, said second signal being digitally encoded, thereby eliminating measurement errors, for example the Seebeck Effect, which occur due to differences in temperature between the sensor, the fluid in the tank, and the processing circuitry mounted within the tank.

A method for monitoring a storage tank containing a fluid, said method including the steps of:

• (a) extending a body into the fluid contained by said tank;
• (b) sensing the force exerted by said fluid upon said body and providing a signal representative of said force;
• (c) providing a second signal, said second signal being digitally encoded, thereby eliminating measurement errors, for example the Seebeck Effect, which occur due to differences in temperature between the sensor, the fluid in the tank, and the processing circuitry mounted within the tank;
• (d) storing a plurality of first values in a lock-up table, each of said first values corresponding to a periodic entry of the force exerted by said fluid upon said body during initial filling of said tank, said first values defining a relationship between the force exerted upon said body at a given fluid depth in said tank and the corresponding fluid mass within said tank, said first values being based on the unique characteristics of said tank, said characteristics including tank shape, volume, orientation, location of said sensor means, and the shape of said body;
• and
• (e) computing a second value representative of the fluid mass within said tank by comparing a subsequent signal representative of the force on said body with said plurality of first values in said look-up table and providing its corresponding fluid mass.