Method and system for measurement of a liquid level in a tank

A method for measuring from a remote location the level of substance in a tank at a user location in which the level is subject to changes, comprising the steps performed by a computer of:

• (a) continuously generating electrical signals representative of differential pressure within the tank and determining values of differential pressure from the generated differential pressure signals;
• (b) generating a signal representative of the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) generating a new collected average signal in response to the instaneous level signal;
• (d) determining the rate of substance depletion during a time window of predetermined duration in response to the new collected average signal, ending the time window at substantially the time of the rate determination;
• (e) receiving by the computer an interrogation signal from the remote location and transmitting the rate to the remote location in response to the interrogation and,
• (f) repeating steps (b) through (e).

A method for measuring from a remote location the level of substnce in a tank of a storage tank system at a user location in which the level is subject to changes and updating a prior collected average level signal of the substance, comprising the steps performed by a computer of:

• (a) continuously generating electrical signals representative of the differential pressure within the tank and determining values of differential pressure from the genenrated dififerential pressure signals;
• (b) generating a signal representative of the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) generaing a difference relationship signal between the prior collected average level signal and the instanteous level signal;
• (d) generating a relative weighting factor signal for the prior collected average level signal and the instantaneous level signal which weighting factor signal varies in accordance with the difference relationship signal;
• (e) generating a new collected average signal in reponse to the relative weighting factor signal;
• (f) comparing by the computer the new collected average signal with a predetermined set point and generating a telecommunication signal when the new collected average signal is below the set point;
• (g) determining by the computer whether selected portions of the system have failed and generating a telecommunication signal when a portion has failed;
• (h) telecommunicating by the computer by placing a phone call to the remote station in response to the telecommunication signal and transmitting set point information and system failure information to the remote location;
• and,
• (i) repeating steps (b) through (h) in which the new collected average signal becomes the prior collected average signal in step (c).

A method for measuring from a remote location the level of substance in a tank at a user location in which the level is subject to changes and updating a prior collected average level signal of the substance, comprising the steps of:

• (a) continuously generating electrical signals representative of differential pressure within the tank and determining values of differential pressure form the generated differential pressure signals;
• (b) generating a signal representative of the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) generating a difference relationship signal between the prior collected average level signal and the instantaneous level signal;
• (d) generating a relative weighting factor signal for the prior collected average level signal and the instantaneous level signal which weighting factor signal varies in accordance with the difference relationship signal;
• (e) generating a new collected average level signal in response to the relative weighting factor signal;
• (f) generaging signals representative of maximum and minimum levels within the tank and the time of occurrence of the maximum and minimum levels;
• (g) receiving interrogation signals from the remote location and transmitting to the remote location the signals representative of the maximum and minimum levels and representative of the determined times in response to the interrogation;
• and,
• (h) repeating steps (b) through (g) in which the new collected average signal becomes the prior collected average signal in step (c).