Method and system for measurement of liquid level in a tank

A method for measuring the level of substance in a tank in which the level is subject to changes and updating a prior collected average level of the substance comprising the steps of:

• (a) continuously determining values of differential pressure from within the tank;
• (b) determining the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) determining a difference relationship between the prior collected average level and the instantaneous level;
• (d) determining a relative weighting factor for the prior collected average level and the instantaneous level which weighting factor varies in accordance with the difference relationship;
• (e) determining a new collected average in response to the relative weighting factor;
• (f) determining the rate of substance depletion in response to the new collected average;
• and
• (g) repeating steps (b) through (f) in which the new collected average becomes the prior collected average in step (c).

A method for determining when to deliver further substance from a remote location to a tank containing substance at a user location in accordance with the level of substance in the tank in which the level is subject to changes comprising the steps of:

• (a) continuously determining values of differential pressure from within the tank;
• (b) determining the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) determining a difference relationship between the prior collected average level and the instantaneous level;
• (d) determining a relative weighting factor for the prior collected average level and the instantaneous level which weighting factor varies in accordance with the difference relationship;
• (e) determining a new collected average in response to the relative weighting factor;
• (f) comparing the new collected average with a first predetermined set point and transmitting a first signal to the remote location when the new collected average is below the first predetermined set point;
• (g) comparing the new collected average with a second predetermined set point and transmitting a second signal to the remote location when the new collected average is below the second predetermined set point;
• and
• (h) dispatching to the user location a vehicle containing the further substance in response to a transmission;
• and
• (i) repeating steps (b) through (g) in which the new collected average becomes the prior collected average in step (c).

A method for measuring the level of substance in a tank in which the level is subject to changes and updating a prior collected average level of the substance comprising the steps of:

• (a) continuously determining values of differential pressure from within the tank;
• (b) determining the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) determining a difference relationship between the prior collected average level and the instantaneous level;
• (d) determining a relative weighting factor for the prior collected average level and the instantaneous level which weighting factor varies in accordance with the difference relationship;
• (e) determining a new collected average in response to the relative weighting factor;
• (f) determining maximum and minimum pressures within the tank and providing a signal to a remote display representative of the maximum and minimum pressures;
• and
• (g) repeating steps (b) through (f) in which the new collected average becomes the prior collected average in step (c).

A method for measuring the level of substance in a tank in which the level is subject to changes and updating a prior collected average level of the substance comprising the steps of:

• (a) continuously determining values of differential pressure from within the tank;
• (b) determining the instantaneous level of substance within the tank in response to the determined values of differential pressure;
• (c) determining a difference relationship between the prior collected average level and the instantaneous level;
• (d) determining a relative weighting factor for the prior collected average level and the instantaneous level which weighting factor varies in accordance with the difference relationship;
• (e) determining a new collected average in response to the relative weighting factor;
• (f) comparing the new collected average with a predetermined setpoint and providing a signal when the new collected averge is below the setpoint;
• (g) telecommunicating with placing a phone call to a remote station in response to the signal and periodically repeating the phone call until the phone call is answered;
• and
• (h) repeating steps (b) through (g) in which the new collected average becomes the prior collected average in step (c).

A method for measuring the level of substance in a tank in which the level is subject to changes and updating a prior collected average level of the substance comprising the steps of:

• (a) continuously determining values of differential pressure from within the tank including analog to digital converting of a differential pressure signal;
• (b) determining whether the converting is operating and providing a signal to a remote display in response to the converting determination;
• (c) determining the instantaneous level of substance within the tank in response to the converted values of differential pressure;
• (d) determining a difference relationship between the prior collected average level and the instantaneous level;
• (e) determining a relative weighting factor for the prior collected average level and the instantaneous level which weighting factor varies in accordance with the difference relationship;
• (f) determining a new collected average in response to the relative weighting factor;
• and
• (g) repeating steps (b) through (f) in which the new collected average becomes the prior collected average in step (d).

A method for measuring the level of substance in each tank of a plurality of tanks in which the level is subject to changes and updating a prior collected average level of substance in each tank comprising the steps of:

• (a) continuously determining values of differential pressure from within each tank;
• (b) determining the instantaneous level of substance within each tank in response to the determined values of differential pressure;
• (c) determining a difference relationship between the prior collected average level and the instantaneous level of each tank;
• (d) determining a relative weighting factor for the prior collected average level and the instantaneous level for each tank which weighting factor varies in accordance with the difference relationship of each tank;
• (e) determining a new collected average for each tank in response to the relative weighting factor of each tank;
• and
• (f) repeating steps (b) through (e) in which the new collected average becomes the prior collected average in step (c).